WHITE 


PHYSIOGRAPHY 

OF 

COLORADO,  UTAH 

AND 

WYOMING 


University  of  California  •  Berkeley 


DEPARTMENT  OF  THE  INTERIOR-TJ.  S,  GEOLOGICAL  SURVEY 
J.  W.  POWELL,  DIRECTOR 


ON  THE  GEOLOGY  AND  PHYSIOGRAPHY 


OF 


A  PORTION  OF  NORTHWESTERN  COLORADO  AND 
ADJACENT  PARTS  OF  UTAH  AND  WYOMING 


BY 


CHARLES   A.   WHITE 


K.KTHACT  FROM  THE  NINTH  ANNUAL  REPORT  OF  THE  DIRECTOR,  1887-'88 


WASHINGTON 

GOVERNMENT   PRINTING   OFFICE 

1890 


ON  THE  GEOLOGY  AND  PHYSIOGRAPHY  OF  A  PORTION  OF 

NORTHWESTERN  COLORADO  AND  ADJACENT 

PARTS  OF  UTAH  AND  WYOMING. 


CHARLES   A.    WHITE. 


677 


CONTENTS. 


Page. 

Topography  of  the  district 683 

Qeological  formations 685 

Archean  rocks 686 

Uinta  sandstone 687 

Carboniferous 688 

Jura-Trias 688 

Cretaceous 689 

The  Dakota  group 689 

The  Colorado  group 689 

The  Fox  Hills  group 689 

The  Laramie  group 690 

Tertiary 690 

The  Wasatch  group 690 

The  Green  River  group 690 

The  Bridger  group 690 

The  Brown's  Park  group 691 

Displacements 691 

The  Uinta  fold 692 

The  Yampa  Plateau  and  other  subordinate  folds 697 

Junction  Mountain  upthrust 701 

Yampa  Mountain  upthrust 702 

Relation  of  the  Uinta  fold  to  other  folds  and  to  the  Park  Range  up- 
lift    703 

Cafions  traversing  the  upthrusts  and  folds 706 

The  Uinta  Canons  of  Green  River 707 

Yampa  Mountain  Canon 708 

Junction  Mountain  Canon 709 

Yampa  Cafion 709 

Concluding  remarks 710 

679 


ILLUSTRATIONS. 


Page. 

PLATE  LXXXVIII.    Geological  map  of  the  district 684 

FIG.  57.  Diagram  representing  the  Uinta  type  of  displacement 693 

58.  A  generalized  transverse  section  of  the  Uinta  fold 694 

59.  Section  across  Eaven  Park,  Midland  Eidge,  and  a  portion  of  the 

main  Uinta  fold 698 

60.  Section  across  Axial  Basin,  5  miles  east  of  Yampa  Mountain 700 

61.  Section  along  a  part  of  the  inceptive  portion  of  the  Uinta  axis 703 

681 


ON  THE  GEOLOGY  AND  PHYSIOGRAPHY  OF  A  PORTION  OF  NORTHWEST- 
ERN COLORADO  AND  ADJACENT  PARTS  OF  UTAH  AND  WYOMING. 


BY  CHARLES  A.  WHITE. 


TOPOGRAPHY  OF  THE  DISTRICT. 

Among  the  many  phenomena  which  are  of  peculiar  interest  con- 
nected with  the  geology  and  physiography  of  the  western  portion 
of  our  national  domain  none  are  more  worthy  of  special  attention 
than  those  occurring  in  the  region  which  embraces  northwestern 
Colorado  and  adjacent  parts  of  Utah  and  Wyoming.  Those  which 
are  to  be  specially  considered  in  this  article  relate  directly  to  geolog- 
ical structure  on  the  one  hand,  and  to  surface  drainage  on  the  other, 
as  these  conditions  now  exist  in  that  region  ;  and  although  the  con- 
ditions referred  to  have  originated  in  forces  which  have  acted  in 
intimate  relation  with  one  another,  they  are  referable  to  two  differ- 
ent categories  of  dynamic  action  that,  were  in  part  complemental 
and  in  part  antagonistic;  that  is,  the  one  category  includes  those 
movements  of  the  earth's  crust  which  have  resulted  in  the  elevation 
of  plateau  and  mountain  masses,  and  the  other  the  forces  which 
have  effected  the  disintegration  and  the  immense  degradation  which 
the  masses  so  elevated  have  suffered. 

The  whole  region  round  about  the  Uinta  Mountains  abounds  in 
striking  topographical  and  geological  features,  the  principal  of  which 
have  been  graphically  described  by  Powell  ; '  but  I  have  selected  for 
special  discussion  a  few  examples  possessing  unusual  interest  which 
pertain  to  each  category,  and  which  occur  within  a  comparatively 
small  district.  This  district  lies  within  that  great  elevated  portion 
of  the  continent  which  Powell  and  Gilbert  have  called  the  Plateau 
Province,3  and  which  is  one  of  the  grandest  fields  for  geological  study 
that  have  ever  been  investigated.  But  as  the  plan  of  this  article  does 
not  embrace  a  detailed  description  of  the  geology  and  topography  of 
the  district  referred  to,  I  shall  present  only  such  descriptions  and 

1  See  Geology  of  the  Uinta  Mountains,  by  J.  W.  Powell ;  and  also  Exploration  of 
the  Colorado  River  of  the  West  and  its  Tributaries. 
5  Geology  of  the  Uinta  Mountains,  pp.  3-7. 

683 


684  GEOLOGY    OF    NORTHWESTERN    COLORADO. 

facts  as  are  deemed  necessary  to  the  elucidation  of  the  special  sub- 
jects selected. 

No  part  of  this  district,  except  a  small  area  immediately  adjacent 
to  Green  River  at  the  south  side  of  the  Uinta  Mountains,  is  less  than 
5,000  feet  above  the  level  of  the  sea,  and  a  large  part  of  the  uneven 
surface  besides  the  mountainous  portion  has  still  greater  elevation. 
Indeed,  the  land  surface  of  this  district  which  I  shall  speak  of  as  low 
when  discussing  the  mountains  is  only  comparatively  so,  for  much 
of  it  has  a  greater  elevation  above  the  sea  than  have  some  important 
mountain  ranges. 

The  foot-hills  of  the  Park  Range,  which  is  a  western  portion  of  the 
great  Rocky  Mountain  system,  lie  along  the  eastern  side  of  the  dis- 
trict. Upon  its  northern  border  lies  the  broad  region  of  open  country 
known  as  Green  .River  Basin  ;  the  eastern  end  of  the  Uinta  Mountain 
range  occupies  the  western  portion,  and  White  River  Valley  lies 
along  its  southern  border. 

While  some  portions  of  the  surface  of  this  district  consist  of  open 
or  comparatively  plain  country,  much  of  it  is  hilly  besides  those  por- 
tions which  may  properly  be  designated  as  mountainous.  Besides 
the  eastern  end  of  the  Uinta  Mountains,  there  are  several  other  promi- 
nent topographic  features  within  the  limits  of  this  district.  The 
Danforth  Hills  rise  upon  the  space  between  Yampa  and  White 
Rivers  in  the  eastern  part  of  the  district.  Yampa  Plateau  and  Mid- 
land Ridge  are  conspicuous  features  of  the  southwestern  part ;  and 
other  more  or  less  isolated  elevations  worthy  of  the  name  of  mount- 
ains, occur  in  different  portions  of  it.  Among  the  latter  are  Junc- 
tion and  Yampa  Mountains,  which,  because  of  their  peculiar  struct- 
ure rather  than  because  of  their  great  prominence  as  topographic 
features,  are  to  receive  special  consideration.  They  are  two  isolated 
mountains  lying  eastward  from  and  in  line  with  the  Uinta  Range. 
They  rise  abruptly  out  of  the  basin  or  broad  valley  through  a  part  of 
which  Yampa  River  flows,  and  which,  for  reasons  that  will  be  made 
obvious,  I  have  called  Axial  Basin. 

The  principal  drainage  of  the  district  is  effected  by  Green  River, 
its  tributaries,  White  and  Yampa  Rivers,  and  by  Snake  River,  a 
tributary  of  the  latter.  Green  River  is  itself  the  principal  tributary 
of  the  Colorado  of  the  West,  or  more  properly  speaking,  it  is  the 
northern  portion  of  that  river  and  ought  never  to  have  received 
another  name. 

This  district  is  a  part  of  the  great  arid  region  of  the  continent,  and 
therefore  the  low-land  tributaries  of  the  rivers  are  mostly  dry  dur- 
ing the  summer,  which  is  the  only  part  of  the  year  during  which 
surveys  are  practicable,  mainly  because  at  other  times  the  excess  of 
water  in  the  rivers  renders  them  unfordable.  That  is,  in  summer 
only  the  main  portions  of  these  rivers,  and  a  few  branches  supplied 
by  perennial  springs,  contain  water,  and  this  is  mostly  derived 


GEOLOGICAL  MAP  OF  A  PORTION  OK  NORTHWESTERN  COUORM 

BY  CHARL 

IN  PART    COMPILED   FROM  THE  PUBLIS 

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AND  ADJACENT  PARTS  OF  UTAH  AND  WYOMING  TERRITORIES. 

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WHITE.]  GEOLOGICAL    FORMATIONS.  085 

from  mountain  tributaries.  Consequently,  while  active  erosion  of 
the  general  surface  is  suspended  there  during  a  large  part  of  the  year» 
direct  corrasion  of  the  river  beds  is  constant.  Passing  mention  may 
be  made  of  the  fact  that  this  constancy  of  corrasion  has  prevailed 
in  that  region  through  a  long  period  of  time,  a  part  of  the  results  of 
which  are  the  numerous  deep  and  narrow  canons  now  found  there. 

In  consequence  also  of  the  general  aridity  of  the  region  during  a 
large  part  of  the  year  vegetation  is  sparse  upon  the  lower  plain  and 
hilly  lands,  which  are  always  the  drier,  and  even  that  of  the  moun- 
tains is  not  usually  sufficient  in  amount  to  materially  hinder  the 
study  of  the  underlying  formations  by  obscuring  them.  This  con- 
dition, together  with  the  rapid  removal  by  erosion  during  the  winter 
months  of  the  debris  resulting  from  the  disintegration  of  the  for- 
mations greatly  facilitates  the  study  of  the  geology  of  that  region. 

Other  important  features  of  this  district  are  its  canons.  These 
will  necessarily  be  referred  to,  and  in  part  described  on  following 
pages.  Those  of  Yampa  Eiver,  although  shorter  and  less  deep  than 
many  others,  will  receive  special  attention  because  of  their  peculiar 
characteristics,  and  of  their  extraordinary  relation  to  Junction  and 
Yampa  Mountains,  and  to  the  Uinta  Range.  Besides  a  discussion 
of  certain  of  the  mountains  and  canons  of  this  district,  evidence 
will  be  presented  that  the  Uinta  and  Rocky  Mountain  ranges  have 
important  structural  relations  with  each  other  although  their  axes 
are  at  nearly  right  angles,  and  although  there  are  considerable  dif- 
ferences between  their  older  rock  formations  respectively. 

Partial  descriptions  of  the  mountains  and  caBons  referred  to  have 
been  published  by  Powell,1  King,2  and  Hague  &  Emmons,3  and  by 
myself,4  but  while  omitting  many  matters  of  great  interest,  I  shall 
attempt  a  somewhat  fuller  presentation  of  the  special  subjects  se- 
lected than  has  heretofore  been  published,  and  try  to  point  out  more 
clearly  the  significance  of  certain  phenomena  which  have  been  ob- 
served there. 

GEOLOGICAL  FORMATIONS  OF  THE  DISTRICT. 

As  the  phenomena  which  it  is  now  proposed  to  discuss  pertain  to 
the  elevation,  displacements,  and  degradation  of  the  great  forma- 
tions of  stratified  rocks  that  prevail  in  the  region  which  embraces 
the  district  before  designated,  it  is  necessary  to  give  some  account  of 
them.  The  following  table  comprises  a  list  of  these  formations, 
beginning  with  the  latest,  together  with  the  estimated  thickness  of 
each  as  they  have  been  measured  in  the  region  embracing  the  eastern 

1  Geology  of  the  Uinta  Mountains. 

2  U.  S.  Geol.  Expl.  40th  Parallel,  vol.  1. 
3U.  S.  Geol.  Expl.  40th  Parallel,  vol.  2. 

«  Annual  Report  U.  S.  Geol.  Surv.  Terr.,  for  1876. 


686 


GEOLOGY   OF   NORTHWESTERN   COLORADO. 


Cenozoic Tertiary 


end  of  the  Uinta  Range.  Following  the  list,  a  description  of  each 
formation  is  given,  so  far  as  is  deemed  necessary  for  the  present  pur- 
pose: 

Table  of  the  Formations. 

Feet. 
Brown's  Park  group 1, 200-  1, 800 

Bridger  group 100-  2, 000 

1  Green  River  group 1,400 

[  Wasatch  group 2, 000-  2, 500 

ILaramie  group ' 2, 000-  3, 000 

Fox  Hills  group 1, 800 

Colorado  group 2, 000. 

Dakota  group 500 

Jura-Trias 2, 500-  5, 000 

(  Carboniferous 3, 000-  4, 000 

I  Uinta  sandstone 12, 000-14, 000 


Mesozoic 


Paleozoic 
Archean. 


Cretaceous  . 


ARCHEAN  ROCKS. 

The  Uinta  Mountain  range  is  unlike  the  Rocky  Mountain  ranges 
in  not  having  the  crystalline  Archean  rocks  exposed  as  a  central  or 
axial  mass.  It  is  highly  probable  that  Archean  rocks  rose  in  the 
axis  of  the  Uinta  fold  during  its  elevation,  somewhat  as  they  are 
represented  in  the  generalized  section,  Fig.  58,  and  as  they  rose  in 
the  erogenic  folds  of  the  Rocky  Mountain  system  where  they  are 
very  conspicuous.  So  far  as  is  known,  however,  they  were  not  suffi- 
ciently elevated  in  the  axis  of  the  Uinta  fold  to  have  become  bared  by 
the  erosion  which  has  given  the  Uinta  Mountains  their  present  form. 
The  only  rocks  of  this  age  which  are  exposed  to  view  in  the  district 
under  discussion,  or  that  are  known  to  be  exposed  in  any  part  of  the 
fold,  are  not  in  its  axis ;  they  occupy  a  small  area  upon  its  northern 
flank,  not  far  from  the  eastern  end  of  the  main  fold.  The  fact  that 
the  Uinta  quartzite  rests  unconformably  upon  these  Archean  rocks 
suggests  the  probability,  first  mentioned  by  Powell,3  that  the  latter 
were  raised  by  a  circumscribed  uplift  in  Archean  time ;  and  that  they 
constituted  an  island  which  remained  such  while  at  least  the  earlier 
part  of  the  Uinta  strata  were  being  deposited.  In  the  subsequent 
elevation  of  the  great  fold  it  is  only  a  part  of  this  island  portion  of 
the  great  Archean  mass  that  has  been  brought  to  view. 

While  these  rocks  are  probably  geologically  eqiiivalent  with  the 
Archean  rocks  of  the  Rocky  Mountain  ranges,  it  is  worthy  of  remark 
that  those  of  the  Uinta  Mountains  present  considerable  lithological 
differences  from  those  of  the  Rocky  Mountain  system.  That  is, 

1  See  remarks  with  foot-note  reference  on  pp.  690,  695,  696. 
*  See  Geology  of  the  Uinta  Mountains,  p.  139. 


WHITE.]  UINTA    SANDSTONE..  687 

although  they  both  contain  similar  component  minerals,  their  pro- 
portions in  the  rocks  of  the  two  ranges  are  very  different.  A  white 
or  light  gray  quartz  is  so  largely  prevalent  in  the  Uinta  Mountain 
Archeaii,  and  the  other  minerals  are  in  such  small  proportion,  that 
Powell  designated  it  as  a  quartzite  in  the  name  which  he  gave  to 
the  formation.1 

These  rocks  not  having  been  observed  in  the  axis  of  the  Uinta  fold, 
it  will  not  be  necessary  to  take  them  any  further  into  consideration 
now,  nor  when  estimating  the  amount  of  vertical  displacement  of 
the  strata  entering  into  that  fold,  except  to  regard  them  as  consti- 
tuting the  floor  of  the  Uinta  quartzite. 

UINTA   SANDSTONE. 

This  great  formation  extends  from  end  to  end  of  the  Uinta  range 
of  mountains  and  constitutes  a  large  part  of  their  bulk.  It  is  also 
found  in  the  isolated  upthrust  mountains  just  beyond  the  eastern 
end  of  the  range  which  have  already  been  mentioned ;  but  it  has  not 
been  recognized  as  such  in  any  part  of  the  Rocky  Mountain  system, 
nor  elsewhere  northward,  southward,  or  eastward  from  the  Uinta 
Range.  This  is  somewhat  remarkable  in  view  of  the  uniform  char- 
acter of  the  formation,  and  of  its  great  thickness  in  that  range 
which,  according  to  Powell,  reaches  a  maximum  of  14,000  feet. 

This  formation  has  usually  a  brown,  or  dark  ferruginous  color, 
and  the  ordinary  regularly  bedded  character  of  sandstone.  In  some 
places  it  has  nearly  the  compactness  of  true  quartzite,  but  usually 
its  hardness  is  that  of  ordinary  firm  sandstone.  In  some  places  soft 
and  shaly  layers  are  found,  but  these  are  exceptional.  As  a  whole, 
the  general  lithological  character  of  the  formation  is  readily  recog- 
nizable ;  and  it  has  considerable  uniformity  throughout  its  geograph- 
ical extent,  and  from  the  lowest  to  the  uppermost  known  strata. 

Much  difference  of  opinion  has  prevailed  as  to  the  true  geological 
age  of  the  Uinta  Sandstone.  King,  who  gave  it  the  name  of  Weber 
Quartzite,  states  that  it  is  of  Carboniferous  age ; '  in  which  view 
Hague  and  Emmons  concur.3  Powell  referred  it  provisionally  to 
the  Devonian ;  *  Marsh  was  disposed  to  regard  it  as  belonging  to  the 
Silurian,5  at  least  in  part;  and  Hayden  was  of  the  opinion  that  it 
ought  to  be  referred  to  the  Lower  Silurian. ' 

'  See  Geology  of  the  Uinta  Mountains,  p.  137. 

SU.  S.  Geol.  Expl.  40th  Parallel,  vol.  1,  pp.  152  and  340. 

3U.  S.  Geol.  Expl.  4th  Parallel,  vol.  2,  pp.  290,  323,  and  452.  In  a  foot-note  to 
page  99,  however,  they  indicate  some  doubt  as  to  the  correctness  of  their  opinion 
as  first  formed. 

1  Geology  of  the  Uinta  Mountains,  p.  141.  But  it  is  proper  to  state  that  I  have 
personal  knowledge  of  the  fact  that  for  the  past  ten  years  Major  Powell  has  regarded 
this  formation  as  of  pre-Cambrian  age. 

5  Am.  Jour.  Sci.,  3d  series,  vol.  1,  p.  193. 

"Ann.  Rep.  U.  S.  Geol.  Surv.  Terr.,  for  1870,  p.  50. 


688  GEOLOGY    OF    NORTHWESTERN    COLORADO. 

Whatever  may  be  the  geological  age  of  the  Uinta  Sandstone,  it  is 
certain  that  the  undoubted  Carboniferous  rocks  of  this  district  rest 
directly  upon  it ;  and,  according  to  Powell,  there  is  in  many  places 
distinct  unconformity  between  them.  It  is  also  true  that  within  this 
district  no  other  rocks  than  the  Archean  have  been  found  beneath 
the  Uinta  Sandstone. 

CARBONIFEROUS. 

The  conditions  attending  the  deposition  of  the  Carboniferous  series 
in  that  far  western  region  were  different  from  those  which  attended 
the  deposition  of  the  rocks  of  the  same  age  in  the  region  drained  by 
the  Missis  ippi ;  and  the  full  series  in  the  two  regions  respectively 
are  therefore  differently  divided.  In  the  region  of  the  Uinta  Mount- 
ains the  Carboniferous  series  has  been  divided  into  three  nominal 
formations,  mainly  upon  lithological  grounds,  all  of  which  are  strictly 
conformable  with  one  another.  The  series  in  this  region  consists  in 
large  part  of  limestones,  but  in  part  of  sandstones,  all  of  which  usu- 
ally are  regularly  bedded,  and  most  of  which  are  compact  and  hard. 
Shaly  or  softer  strata  rarely  occur  among  them,  and  coal,  which  so 
distinctly  characterizes  the  series  elsewhere,  has  never  been  discov- 
ered among  its  strata  there.  Because  of  this  strict  conformity  of  the 
three  nominal  formations  of  the  Carboniferous  scries  with  one  an- 
other in  this  region,  and  the  generally  firm  character  of  all  the 
strata  composing  them,  the  whole  series  will  be  treated  as  a  single 
unit  in  the  following  discussions. 

Attention  should  here  be  called  to  the  fact  that  the  Paleozoic  strata, 
that  is,  those  of  the  Uinta  and  Carboniferous  formations,  consist  as 
a  whole  of  much  harder  rocks  than  those  of  the  later  formations,  de- 
scriptions of  which  now  follow. 

JURA-TRIAS. 

Resting  comformably  upon  the  Carboniferous  in  this  district  there 
is  a  series  of  sandstones  which  have  usually  been  regarded  as  of  Tri- 
assic  age,  but  it  is  probable  that  the  lower  portion  ought  to  be 
assigned  to  the  Carboniferous  series.  These  sandstones  consist  of 
yellowish,  moderately  firm  strata  above,  of  yellowish  softer  strata 
below  ;  and  between  them  a  thick  mass  of  bright  red  or  brownish- 
red  strata,  most  of  which  are  moderately  firm.  The  Triassic  age  of 
all  of  them  except  the  lower  portion  just  mentioned,  has  rarely 
been  questioned  ;  but  the  strata  of  that  portion  being  usually  barren 
of  fossils,  its  geological  age  has  not  been  determined  with  as  much 
accuracy  as  could  be  desired. 

Upon  the  Triassic  sandstones  comes  a  small  series  of  beds  which  are 
usually  referred  definitely  to  the  Jurassic.  They  consist  of  soft, 


WHITE.]  CRETACEOUS.  689 

variegated  bad-land'  sandstones',  with  occsionally  harder  layers ; 
and  near  the  base  of  this  comparatively  thin  series  of  strata,  a  few 
feet  in  thickness  of  sandy,  shaly,  or  often  calcareous,  fossiliferous 
layers,  are  usually  found.  This  Jurassic  portion  of  the  Jura-Trias 
series  is  hardly  more  than  one-fifth  of  the  whole  in  thickness,  but 
its  distinguishing  characteristics  are  quite  uniform  over  a  wide  geo- 
graphical area. 

CRETACEOUS. 

The  full  Cretaceous  series  in  this  district,  exclusive  of  the  Laramie, 
reaches  a  thickness  of  4,300  feet ;  and  the  Laramie  has  hero  a  thick- 
ness of  2,000  to  3,000  feet  additional.  In  accordance  with  the  views 
expressed  by  me  on  a  former  occasion2 1  here  place  the  Laramie  among 
the  Cretaceous  formations.  This  arrangement  is  the  more  desira'blo 
in  the  present  case  because  the  stratigraphical  and  not  the  paleonto- 
logical  relations  of  the  formations  are  discussed.  That  is,  in  these 
discussions  prominence  is  necessarily  given  to  the  fact  that  not  only 
does  the  Laramie  group  rest  comformably  upon  the  marine  Cretace- 
ous, but  the  former  group  is  fully  involved  with  all  the  formations 
earlier  than  itself  in  all  the  displacements  which  are  mentioned  as 
having  occurred  in  this  district,  while  the  later  formations  were  not 
thus  fully  involved. 

The  Dakota  Group,  the  lowennost  of  the  Cretaceous  series  in  this 
region,  and  the  equivalent  of  No.  1  of  the  Upper  Missouri  section  of 
Meek  &  Hayden,  here  presents  nearly  the  same  general  characteris- 
tics which  it  possesses  throughout  the  great  Rocky  Mountain  region. 
The  upper  portion  consists  of  yellowish  or  brown  rough  sandstone, 
the  middle  portion  of  variegated  sandstone,  and  the  lower  portion  of 
irregularly  bedded  pebble  conglomerate.  The  strata  are  generally 
firm,  and  their  escarpments  prominent. 

The  Colorado  Group,  the  equivalent  of  Nos.  2  and  3  of  Meek  & 
Hayden,  consists  in  this  district  of  dark  colored  argillaceous  shales, 
and  clayey  and  sandy  strata,  with  occasional  layers  of  moderately 
firm  sandstones.  All  these  strata  are  so  soft  that  they  seldom  appear 
in  escarpments ;  and  because  of  the  facility  with  which  they  are 
eroded  they  have  given  place  to  certain  of  the  basins  and  broader 
valleys. 

The  Fox  Hills  Group,  the  equivalent3  of  Nos.  4  and  5  of  Meek  & 

1  The  Mauvaises  Torres  or  Bad-Lands  of  the  Wast  are  usually  covered  with  debris 
which  is  often  so  soft  as  to  yield  to  the  pressure  of  the  foot ;  but  the  material  before 
erosion  is  almost  always  a  soft  earthy  sandstone,  designated  as  bad-land  sand- 
stone. 

a  See  White, C.  A.,  on  the  relation  of  the  Laramie  Group  to  earlier  and  later  for- 
mations :  Am.  Jour.  Science,  3d  series,  Vol.  35,  pp.  432-438. 

3Since  this  article  was  written  I  have  adopted  the  name  Montana  Group  pro- 
posed by  Mr.  Geo.  H.  Eldridge  for  the  equivalent  of  Nos.  4  and  5  of  the  Upper  Mis- 
souri section.     See  Am.  Jour.  Sci.,  Vol.  XXXVIII,  Oct.  1889,  pp  313-321. 
9  GEOL 44: 


690  GEOLOGY    OF    NORTHWESTERN    COLORADO. 

Hayden,  here  presents  some  differences  in  lithological  character  from 
that  which  it  possesses  in  other  districts.  The  upper  part  consists 
mainly  of  the  more  common,  somewhat  soft  sandstones,  but  the  lower 
portion  is  so  largely  made  up  of  soft,  sandy,  and  argillaceous  shales, 
similar  to  the  shales  of  the  Colorado  Group,  that  in  the  absence  of 
characteristic  fossils  it  is  difficult  to  distinguish  the  two  formations 
apart  where  they  are  found  in  contact. 

The  Ltirit/iiif  Group  consists  mainly  of  sandstones  and  sandy  shales. 
The  sandstones,  while  not  often  very  hard,  are  frequently  so  linn 
that  they  form  abrupt  escarpments  ;  and  they  also  form  prominent 
hogbacks  when  tilted  at  a  high  angle.  The  absence  of  true  marine 
fossils  in  this  great  formation,  and  the  presence  throughout  its  wide 
geographical  extent  of  such  forms  as  now  characterize  freshand  bra.ck- 
ish  waters  is  worthy  of  notice.  These  facts  indicate  that  the  forma- 
tion was  deposited  in  a  great  inland  sea,  or  one  which  was  largely 
cut  off  from  the  open  ocean  by  land  barriers  which  were  elevated  at 
the  close  of  the  Fox  Hills  epoch.  These  barriers  probably  did  not 
reach  any  considerable  height  above  the  sea  ;  or  at  least  their  eleva- 
tion was  evidently  not  a  part  of  the  orogenic  movements  which  began 
at  the  close  of  the.  Laramie  period,  and  resulted  in  the  production  of 
the  Uinta,  and  other  great  folds  upon  a  broad  and  rising  continental 
area. 

TERTIARY. 

The  Tertiary  strata  of  this  district  are  all  of  fresh-water  origin, 
and  are  divided  into  four  groups.  The  three  lower  ones  are  usually 
referred  to  the  Eocene  without  hesitation ;  while  the  upper  one  is 
sometimes  referred  to  the  Eocene,  sometimes  to  the  Miocene,  and 
sometimes  to  the  Pliocene.  The  three  lower  groups  are  strictly  con- 
formable with  one  another,  and  the  lowest  one  appears  in  this  dis- 
trict to  rest  conformably  upon  the  Lamarie,  where  the  contact  has 
been  observed.  The  upper  or  Brown's  Park  group,  however,  is  con- 
spicuously unconfortnable  with  the  other  Tertiary  formations,  as  well 
as  with  all  the  other  formations  with  which  it  is  found  in  contact. 

The  Wasatch  Group,  the  equivalent  of  the  Bitter  Creek  group  of 
Powell  and  of  the  Vermillion  Creek  group  of  King,  consists  in  this 
district  of  alternating  harder  and  softer  sandstones  below,  and  of 
bad-land  sandstones  above. 

The  Green  River  Group  consists  of  coarse,  irregularly  bedded 
sandstone  above,  and  sandy  and  calcareous,  with  occasionally  car- 
bonaceous, layers  below,  which  are  generally  thin  bedded,  and  occa- 
sionally shaly.  The  maximum  thickness  of  both  divisions  in  this 
district  is  only  about  1,400  feet,  which  is  about  equal  to  the  full 
thickness  that  this  formation  is  known  to  have  elsewhere. 

The  Bridger  Group  reaches  a  thickness  of  only  about  100  feet  in 
this  district,  but  northwestward  from  this  district  it  has  been 


WHITE.]  DISPLACEMENTS.  691 

observed  to  reach  a  maximum  thickness  of  about  2,000  feet.  It  con- 
sists mainly  of  bad-land  sandstones,  but  sometimes  the  layers  have 
considerable  firmness. 

The  Brown's  Park  Group  is  regarded  as  equivalent  to  the  Uinta 
group  of  King.'  The  latter  name  was  given  by  King  to  those  strata 
of  the  group  that  occur  on  the  south  side  of  the  eastern  end  of  the 
Uinta  range ;  but  he  did  not  recognize  those  upon  the  north  and 
east  sides  as  being  different  from  the  Green  River  group.'  The 
southern  portion  presents  a  reddish  or  yellowish  ferruginous  aspect; 
while  the  northern,  and  eastern  portions  have  throughout  an  unus- 
ually light  color.  This  difference  in  color  is  perhaps  due  to  the  deri- 
vation of  material  from  the  red  Triassic  sandstones  in  the  one  case, 
and  from  the  light-colored  Bridger  and  Green  River  groups  in  the 
other. 

The  Brown's  Park  group  consists  mainly  of  sandy  material, 
iisually  fine  grained,  with  occasionally  gravelly  strata.  The  strata 
are  sometimes  evenly  bedded  and  firm,  but  they  are  often  irregular 
and  friable ;  and  they  are  frequently  incoherent  where  exposed  at 
the  surface.  Because  it  rests  uncoiiformably  upon  all  the  other 
formations  witli  which  it  conies  in  contact,  it  obscures  the  underly- 
ing geological  structure  in  numerous  places ;  but  seldom  to  such  an 
extent  as  to  leave  the  real  character  of  the  structure  in  doubt. 

Besides  the  formations  described  in  the  foregoing  paragraphs 
there  are  certain  later  surface  accumulations  ;  but  as  they  have  no 
necessary  relation  to  the  special  subjects  of  this  article  they  are  not 
represented  upon  the  accompanying  map ;  and  they  are  mentioned 
here  only  by  name.  They  are  the  Bishop's  Mountain  Conglomerate 
(=  Wyoming  Conglomerate  of  King),  the  local  drift  derived,  appar- 
ently by  glaciation,  from  both  the  Uinta  and  Park  ranges,  and  the 
Quaternary  deposits  of  the  river  valleys.  Eruptive  rocks  are  also 
found  in  the  eastern  part  of  the  district,  as  represented  upon  the  ac- 
companying map ;  but  a  description  of  them  is  not  deemed  necessary 
for  the  present  purpose. 

DISPLACEMENTS. 

The  displacements  which  these  formations  have  suffered  in  this 
district  are  numerous,  and  some  of  them  are  of  great  vertical  ex- 
tent. They  are  mainly  in  the  form  of  folds  or  of  more  circumscribed 
uplifts,  and  of  more  or  less  conspicuous  tiltings.  The  principal  dis- 
placement within,  or  that  reaches  within,  this-district  is  the  great 
Uinta  fold. 

1  Not  the  Uinta  group,  or. Uinta  quartzite  of  Powell  (op.  cit.). 

3  See  Atlas  U.  S.  Geol.  Expl.  40th  parallel,  Map  II,  east  half.  Also  compare  with 
the  map  accompanying  this  article,  and  with  map  B,  of  atlas  of  Geology  of  the 
Uinta  Mountains. 


692  GEOLOGY    OF    NORTHWESTERN    COLORADO. 

THE   UINTA   FOLD. 

This  fold  has  usually  been  described  as  having  its  eastern  end 
terminating  abruptly  in  northwestern  Colorado.  As  a  conspicu- 
ous fold  it  does  so  terminate ;  but  continuous  with  its  axis  to  the 
eastward  there  is  a  long  gentle  anticline  which  reaches  by  a  broad 
curve  to  the  foot-hills  of  the  Park  Range,  and  which  I  regard  as  a 
continuation  of  the  Uinta  fold.  I  therefore  divide  the  Uinta  fold 
into  two  portions,  namely,  the  main  portion  or  the  Uinta  fold  proper, 
and  the  inceptive  portion  of  the  same.  For  convenience  of  descrip- 
tion I  shall  so  designate  them  in  this  article. 

Both  Powell'  and  King2  have  shown  that  the  Uinta  fold  is  com- 
posed of  a  series  of  formations  of  stratified  rocks  of  great  thickness, 
which  have  all  been  elevated  together  along  an  approximately  east 
and  west  axis.  The  fold  proper  is  about  one  hundred  and  fifty  miles 
in  length,  and  from  thirty  to  forty  miles  in  width  at  the  extreme  limit 
of  the  upturned  strata  at  either  side.  Its  western  end  is  blended  with 
the  Wasatch  Range  in  Utah,  which  it  meets  at  nearly  right  angles. 
Its  eastern  terminus  is  about  thirty  miles  within  and  east  of  the 
western  boundary  of  Colorado,  and  about  the  same  distance  from 
the  northern  boundary.  Its  axis  is  not  quite  straight,  the  maps  of 
its  surveys  showing  gentle  and  somewhat  irregular  meanderings. 
One  of  these  gives  its  eastern  end  a  gentle  curve  a  little  to  the  south 
of  its  general  course,  which  brings  it  into  line  with  the  curved  axis 
of  the  inceptive  portion  of  the  fold. 

This  great  fold  is  remarkable  for  its  simplicity  and  its  peculiar 
characteristics,  as  compared  with  the  other  erogenic  displacements 
which  have  occurred  in  that  great  region;  that  is,  while  its  western 
end  blends  with  the  Wasatch  Range,  and  its  eastern  end  has  structu- 
ral relation  with  the  Rocky  Mountain  system,  the  great  fold,  as  a 
whole,  has  certain  characteristics  peculiarly  its  own,  and  it  has  also 
few  lateral  complications.  It  is  true  there  are  certain  minor  plica- 
tions adjacent  to  the  range ;  but,  with  the  exception  of  the  Yampa 
Plateau3  fold,  these  are  comparatively  small  and  inconspicuous. 

It  is  out  of  the  formations  which  were  brought  up  in  the  great 
Uinta  fold  that  the  mountain  range,  as  we  now  know  it,  has  been 
carved.  This  carving  has  been  accomplished  by  the  ordinary  pro- 
cess of  erosion  which  is,  and  always  has  been,  in  constant  action  upon 
the  surface  of  the  earth ;  but  it  has  here  been  effected  upon  a  scale 
of  such  magnitude  that  the  present  majestic  peaks  may  be  properly 
regarded  as  only  shreds  of  the  enormous  mass  which  has  been  up- 
lifted there.  Some  of  the  higher  peaks  of  the  range  have  now  a 

1  Geology  of  the  Uinta  Mountains. 

»U.  S.  Geol.  Expl.  40th  Parallel,  vol.  1. 

•Yarapa  Plateau  must  not  be  confounded  with  Yampa  Mountain.  Separate 
names  for  each  would  be  used  here  if  it  were  deemed  expedient  to  change  either  of 
them  after  their  long  publication  and  use. 


WHITE.]  THE    UINTA    FOLD.  -693 

height  of  more  than  7,000  feet  above  the  general  surface  of  the  sur- 
rounding region ;  and  the  elevation  of  the  region  itself  is  so  great 
that  the  summits  of  those  higher  peaks  are  more  than  13,000  feet 
above  the  level  of  the  sea. 

Powell  has  shown  that  the  Uinta  fold  is  of  a  peculiar  type,1  being 
characterized  by  an  abrupt  upward  flexure  of  the  strata  at  either 
side,  which  in  some  places  is  a  true  fault,  while  between  the  two 
abrupt  side  flexures  the  fold  is  broad,  and  its  convexity  compara- 
tively gentle. 


Fio.  57.  Diagram  representing  the  Uinta  type  of  displacement. 

The  accompanying  diagram  (Fig.  57)  copied  from  Powell,  illus- 
trates this  peculiar  form  which  he  designated  as  the  Uinta  type  of 
displacement.  This  peculiar  type  characterizes  not  only  the  main 
fold,  but  it  is  recognizable  in  some  of  its  subordinate  uplifts;  for  ex- 
ample, in  the  midland  and  Yampa  Plateau  folds. 

Before  proceeding  with  a  description  of  the  great  fold  it  is  proper 
to  refer  to  some  other  matters  which  are  of  general  importance  in 
this  connection.  Attention  has  been  called  to  the  fact  that  the  Car- 
boniferous and  Uiiita  Sandstone  formations  are  mainly  composed  of 
hard  rocks.  The  later  formations,  from  the  Jura-Trias  to  the  Lara- 
mie  inclusive,  although  their  strata  are  often  firm,  are,  as  a  whole, 
composed  of  softer  rocks,  many  of  them  yielding  readily  to  disinte- 
grating action.  The  same  may  be  said  of  the  three  lower  Tertiary 
formations,  while  the  upper  one,  or  Brown's  Park  group,  is  in  still 
larger  part  composed  of  friable  materials.  It  should  be  further 
mentioned  that  all  these  softer  formations  are  mainly  composed  of 
siliceous  sand. 

These  facts  are  mentioned  here  because  of  their  bearing  upon  the 
question  of  the  origin  of  the  present  remarkable  topographic  feat- 
ures of  this  region.  One  may  readily  understand  that  if  the  earlier 
formations  had  consisted  of  softer  rocks  than  the  later  ones,  the 
topographic  features  resulting  from  their  displacements  and  from 
the  erosion  which  the  whole  have  suffered,  would  have  been  very 
different  from  what  they  now  are.  Again,  one  quickly  reaches  the 
conclusion  that  it  is  the  siliceous  materials  of  the  softer  formations 
that  have  been  made  the  instrument  of  corrasion  of  the  harder  rocks, 
which  fact  will  presently  be  discussed. 

Other  conditions  being  equal  the  rapidity  and  extent  of  disinte- 
gration and  erosion  would  depend  largely  upon  the  varying  hardness 
of  the  rocks  thus  .effected,  but  it  is  not  always  the  case  that  the  softer 

1  Geology  of  the  Uinta  Mountains,  p.  17. 


694 


GEOLOGY   OF   NORTHWESTERN    COLORADO 


rocks  have  suffered  most  in  this  respect.  In  fact,  the  hardest  rocks 
have  yielded  to  such  action,  and  to  the  more  direct  action  of  corra- 
sion,  to  a  surprising  extent,  and  in  this  district  numerous  examples 


are  found  which  seem  to  show  that  they  have  offered  as  little  resist- 
ance to  erosion  as  the  softer  rocks  have  done,  and  in  some  cases,  at 
least,  they  seem  to  have  offered  less  resistance  to  the  corrasive  action 
of  rivers  than  have  the  softer  rocks.  The  reason  for  making  this 
latter  suggestion  will  be  made  apparent  in  the  following  paragraphs 
which  refer  to  river  caflons. 

It  is  the  softer  rocks  which  have  yielded  the  instrumental  material 
for  the  corrasion  of  the  cafions  in  the  harder  formations.     If  there 


WHITK.]  THE    UINTA    FOLD.  695 

had  been  no  thick  formations  of  hard  strata  there  could  have  been 
no  narrow,  deep  canons,  and  if  there  had  been  no  extensive  forma- 
tions of  friable  siliceous  rocks  in  the  same  or  adjacent  district  the 
canons  could  not  have  been  cut  for  the  want  of  the  proper  instru- 
ment. In  short,  and  as  has  already  been  mentioned,  it  is  sand, 
together  with  other  rock  fragments,  that  has  served  as  the  instru- 
ment of  corrasion,  while  the  moving  water  of  the  rivers  has  served 
as  the  vehicle  for  transporting  the  instrument,  and  as  the  medium 
for  applying  the  power  by  which  the  corrasion  was  accomplished. 

Let  us  now  return  to  a  consideration  of  the  great  Uiiita  fold.  The 
study  of  the  present  geological  structure  of  a  region  enables  us  to 
reach  important  conclusions  as  to  the  past  geological  history  of  that 
portion  of  the  earth  of  which  it  forms  a  part.  Such  a  study  of  the 
region  round  about  the  Uinta  Mountains  shows  that  the  formations 
there  were  not  all  equally  involved  in  the  great  fold.  The  present 
condition  of  those  formations  and  their  relation  to  one  another,  show 
that  all  of  them,  from  the  Uiiita  sandstone  to  the  Laramie  inclusive, 
were  equally  involved  in  that  fold,  while  the  relation  of  the  Tertiary 
formations  to  those  older  ones,  show  that  these  were  only  partially 
involved  in  it.  These  relations  of  the  formations  to  one  another, 
and  to  the  great  fold,  are  graphically  illustrated  by  the  accompany- 
ing generalized  section  of  the  Uinta  fold.  (Fig.  58.) 

From  the  foregoing,  and  other  correlated  facts,  the  inference  is 
drawn  that  the  elevation  of  the  great  Uinta  fold  was  begun  imme- 
diately upon  the  close  of  the  Laramie  period,  and  before  the  first  of 
the  fresh-water  Tertiary  strata  were  deposited  ;  and  that  it  was 
nearly  complete  before  the  deposition  of  the  Brown's  Park  group  ; 
the  latest  of  the  fresh-water  Tertiary  series.  Other  facts  already 
referred  to,  indicate  that  the  waters  in  which  the  Laramie  group 
was  deposited  rested  at  a  level  which  was  little,  if  any,  above  that 
of  the  open  sea  ;  and  the  character  and  present  condition  of  the 
Tertiary  formations  show  that  they  were  successively  deposited  at 
respectively  different  heights  above  that  level.  That  is,  they  were 
deposited  in  great  lakes,  the  existence,  extent  and  elevation  of  which 
were  respectively  determined  by  the  varying  configuration  of  the 
general  land  surface  as  elevation  and  degradation  progressed. 

The  facts  which  have  been  presented  show  that  the  orogenic 
movements1  which  have  resulted  in  the  production  of  the  Uinta  and 
other  mountain-making  folds  were  approximately  synchronous  in 
their  origin,  and  coeval  as  to  time- limits  of  their  duration,  with  the 
epirogenic  movements  by  which  the  great  continental  area  upon 
which  those  folds  rest  reached  its  present  elevation.1  These  con- 

1  Certain  epirogenic  movements  must  necessarily  have  taken  place  to  form  the 
barriers  by  which  the  Laramie  sea  was  cut  off  from  the  open  oceans.  Local  un- 
conformity among  the  Laramie  strata,  which  has  been  observed  near  the  top  of  the 
group  in  southern  Wyoming,  indicates  that  certain  other  premonitory  movements 
took  place  before  the  Uinta  fold  was  well  defined. 


696  GEOLOGY    OF   NORTHWESTERN    COLORADO. 

elusions,  and  the  facts  upon  which,  they  are  based,  are  of  importance 
in  estimating  the  amount  of  vertical  displacement  which  has  taken 
place  in  the  Uinta  fold,  because  they  constitute  the  data  by  which 
we  determine  the  upper  and  lower  limits  of  the  series  of  formations 
which  were  wholly  involved  in  it,  and  which  alone  need  to  be  con- 
sidered in  that  immediate  connection. 

In  the  case  of  many  mountain  ranges  it  is  difficult  to  estimate  the 
amount  of  vertical  displacement  which  has  taken  place  in  their  ele- 
vation. But  the  Uinta  Range  and  its  foot-hills  being  composed 
almost  entirely  of  a  series  of  at  least  approximately  comformable 
formations  of  stratified  rocks,  the  thickness  of  each  of  which  has 
been  ascertained,  an  estimate  of  the  amount  of  vertical  displacement 
there  may  be  made  with  a  good  degree  of  confidence  in  its  general 
accuracy. 

The  formations  later  than  the  Laramie  not  having  been  involved 
in  the  beginning  of  the  uplift,  and  the  Archean  rocks  not  being  ex- 
posed in  the  heart  of  the  Uinta  Range,  both  are  excluded  from  the 
estimate  here  given.  This  estimate  is  based  upon  the  ascertained 
thickness  of  each  of  the  formations  from  the  Uiuta  sandstone  to  (lie 
Laramie,  inclusive,  the  elevation  above  the  sea  of  the  lowermost  ob- 
served strata  of  the  Uinta  sandstone,  and  upon  the  fact,  as  assumed, 
that  the  top  of  the  Laramie  was  little,  if  any,  above  the  level  of  the 
sea  when  the  upward  movement  of  the  fold  began. 

In  making  this  estimate  I  have  thought  best  to  use  the  minimum 
thickness  of  each  formation  as  given  in  the  foregoing  table,  lest  I 
should  appear  disposed  to  exaggerate  a  statement  of  facts  which  are 
obviously  so  remarkable.  The  aggregate  thickness  of  the  forma- 
tions from  the  Uinta  sandstone  to  the  Laramie,  inclusive,  is  thus 
found  to  be  23,800  feet.  Add  to  this  5,000  feet  as  the  height  above 
the  sea  at  which  the  lowermost  strata  of  the  Uinta  sandstone  have 
been  observed,  and,  we  have  an  aggregate  of  28,800  feet,  or  about 
five  and  a  half  miles. ' 

It  is  of  course  not  to  be  understood  that  even  the  uppermost  of  the 
strata  of  the  uplifted  series  ever  reached  a  height  above  the  level  of 
the  sea  at  all  approximating  the  full  amount  of  vertical  displace- 
ment. In  fact,  we  have  no  reason  to  suppose  that  any  portion  of  the 
Uinta  Range  ever  attained  a  much  greater  height  than  the  higher 
peaks  now  have,  because  erosion  of  even  the  hardest  rocks  closely 
balances  elevation  after  certain  heights  are  reached. 

'Accepting  Powell's  statement  as  to  the  marked  unconformity  between  the  base 
of  the  Carboniferous  and  the  top  of  the  Uinta  sandstone,  and  his  views  as  to  the  pre- 
Cambrian  age  of  the  latter,  geologists  will  readily  perceive  their  great  significance. 
But  these  facts  and  conclusions  do  not  necessarily  affect  the  estimate  here  given  of 
the  amount  of  vertical  displacement  in  the  Uinta  fold.  They  point  to  a  great  blank 
in  geological  history  as  regards  the  region  here  discussed,  the  closing  epoch  of 
which  was  long  anterior  to  any  of  the  movements  and  displacements  described  and 
referred  to  in  this  article. 


WHITE.]  SUBORDINATE   FOLDS.  697 

The  readier  yielding  of  the  softer  than  of  the  harder  rocks  to  dis- 
integrating and  erosive  action  under  like  conditions  has  already  been 
referred  to.  This  fact  has  seeming  exemplification  in  the  presence 
of  the  older  and  harder  rocks  in  the  higher  mountains  in  this  dis- 
trict, and  the  removal  of  the  later  and  softer  ones  from  the  more 
elevated  portions  of  the  uplifts,  which  must  necessarily  have  once 
rested  there.  But  it  must  be  borne  in  mind  that  it  would  have  been 
impossible  for  even  the  harder  strata  to  resist  the  constantly  active 
forces  of  degradation,  at  the  great  heights  to  which  the  softer  ones 
would  have  been  carried,  if  they  had  not  been  removed  by  erosion 
while  they  were  being  elevated.  With  these  explanations  we  will 
now  consider  certain  other  topographic  and  structural  features  of 
this  district  which  it  is  the  object  of  this  article  to  -discuss. 

The  eastern  terminus  of  the  Uinta  fold  proper  'is  by  a  dip  of  its 
greatly  elevated  strata,  which  is  quite  as  abrupt  as  it  is  at  the  sides 
of  the  fold.  This  terminal  dip  has  a  broadly  sweeping  semi-elliptic 
trend,  which  is  marked  by  the  upturned  edges  of  the  later  forma- 
tions that  were  involved  in  the  fold,  as  they  also  mark  the  trend  of 
the  dip  at  either  side.  These  later  formations  having  suffered  com- 
plete erosion  from  a  broad  space  on  either  side  of  the  axis  of  the  fold, 
the  present  mountains  are  found  to  be  composed  of  the  earlier  forma- 
tions almost  alone,  while  the  characteristic  lateral  dips  are  mainly 
observable  in  the  later  ones. 

The  semi-elliptic  form  of  the  trend  of  the  upturned  strata  is  due 
to  the  preservation  of  the  type  of  uplift  of  the  fold,  even  to  its  very 
end.  The  upturned  strata  which  mark  that  trend,  however,  are  to  a 
considerable  extent  obscured  from  view  upon  the  northern  side. 
This  is  in  part  due  to  a  remarkable  down  throw  of  the  strata  which 
were  there  involved  in  the  fold,  as  has  been  shown  by  Powell.1  and 
in  part  to  the  presence  there  of  the  later  Tertiary  formation  which 
bears  the  name  of  the  park,  as  already  described. 

The  termination  of  the  great  fold  by  a  sudden  dip  while  preserv- 
ing nearly  its  full  width  is  worthy  of  remark,  because  it  shows  that 
the  main  portion  of  the  fold  does  not  pass  gradually  into  the  incep- 
tive portion.  This  condition  might  perhaps  be  regarded  as  an  indica- 
tion that  the  latter  portion  is  not  really  a  continuation  of  the  former 
if  it  were  not  true  that  similar  conditions  are  observable  in  the  case 
of  other  displacements  which  are  immediately  connected  with  both 
the  great  fold  and  its  inceptive  portion.  But  this  subject  will  be 
further  considered  in  following  paragraphs. 

THE  YAMPA  PLATEAU,  AND  OTHER  SUBORDINATE  FOLDS. 

Before  proceeding  eastward,  along  the  inceptive  portion  of  the 
Uinta  fold,  however,  let  us  briefly  consider  three  subordinate  up- 

'Geol.  Uinta  Mountains,  pp.  208,  209. 


698 


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GEOLOGY    OF    NORTHWESTERN    COLORADO. 

lifts  which  lie  adjacent  to  the  southern  side 
of  the  eastern  end  of  the  main  fold  and 
another,  the  Danforth  Hills  uplift,  which 
lies  adjacent  to  the  south  side  of  the  incep- 
tive portion  of  that  fold.  Two  of  the  first 
mentioned  uplifts  are  in  the  form  of  some- 
what short  folds  which  lie  closely  adjacent 
to  each  other,  as  well  as  to  the  maiii  fold, 
with  the  axis  of  which  the  axes  of  these  two 
subordinate  folds  are  approximately  paral- 
lel. They  are  designated  as  the  Yam  pa 
Plateau  and  the  Midland  folds,  respect- 
ively. The  third  one.  which  I  have  called 
Raven  Park  uplift,  lies  toward  the  south 
near  to,  but  not  adjoining,  the  others.  It 
is  approximately  oval  in  outline,  has  a  less 
vertical  displacement  than  the  others,  and 
the  direct  ion  of  its  longer  diameter  is  nearly 
northwest  and  southeast. 

It  will  lie  observed  that  these  subordi- 
nate folds  are  clustered  together  at  the 
south  side  of  the  eastern  terminus  of  the 
main  portion  of  the  great  fold;  that  the 
two  larger  ones  terminate  suddenly,  espe- 
cially at  the  eastern  end,  as  does  the  great 
fold;  and  that  beyond  these  abruptly  ter- 
minating ends  there  are  no  indications  of 
a  continuation  of  their  axes. 

The  lateral  relation  of  these  subordinate 
folds  to  one  another  and  to  the  main  fold  is 
shown  in  the  accompanying  section,  Fig. 
f>li.  the  line  of  which  is  across  them,  and  ap- 
proximately upon  the  meridian  of  108°  50'.' 
The  topographic  feature  known  as  Yam- 
pa  Plateau  is  so  closely  blended  with  the 
mountains  of  the  Uinta  Range  that  it  may 
properly  be  regarded  as  a  part  of  the  same. 
It  includes  the  western  portion  of  the  Mid- 

•B  g  'The  section  F.  F.,  which  is  given  at  the  bottom 

§•  "^  of  the  map  facing  page  60  of  Ann.  Rep.  TJ.  S.  Geol. 

•g  ^  Surv.  Terr.,  for  1876,  was  intended  to  represent  the 

P«  •„-  same  strata  and  their  displacemeats  which  are  rep- 
resented in  this  figure.     That  section,  however,  in  in- 

ig  :a  correct,  and  was  published  without  an  opportunity 

o"  %  having  been  given  the  author  of  the  report  to  cor- 

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WHITE.]  YAMPA    PLATEAU    FOLD.  699 

land,  as  well  as  that  of  the  plateaii  fold,  but  it  does  not  extend  to  the 
eastern  portion  of  either  of  them.  My  present  object, however,  is  to 
refer  to  the  folds  as  a  part  of  the  series  of  displacements  which  it  is 
the  special  object  of  this  article  to  consider,  rather  than  to  describe 
topographic  features. 

Yampa  Plateau  fold  is  about  40  miles  long  from  its  eastern  to  its 
western  terminus.  Its  vertical  displacement  has  been  so  great  as  to 
bring  up  the  Carboniferous  rocks,  which,  by  erosion  of  the  later  for- 
mations, are  exposed  at  the  surface  along  its  whole  length,  leaving 
those  later  formations  upturned  at  the  ends  of  the  fold.  The  east- 
ern end  terminates  as  suddenly  as  that  of  the  main  fold  by  a  simi- 
lar broadly  sweeping  dip  of  its  strata,  and  at  a  point  only'  a  little 
further  westward  than  the  terminus  of  the  main  fold.  Its  western 
termination  is  by  two  prominent  spurs,  called  respectively  Split 
Mountain  and  Section  Ridge.  Unlike  most  spurs  which  are  projected 
from  mountain  ranges,  these  are  quite  regular  in  structure.  Each  is 
closely  like  the  other  in  this  respect,  as  well  as  in  their  dimensions 
and  in  the  extent  of  the  vertical  displacement  which  their  strata 
have  suffered.  The  central  portion  of  each  is  composed  of  Carbonifer- 
ous rocks,  which  are  continuous  with  those  of  the  main  mass  of  the 
plateau,  while  the  Mesozoic  rocks  are  upturned  all  round  their  base 
as  they  are  around  the  other  uplifts  in  this  district. 

The  axis  of  the  Split  Mountain  spur  extends  nearly  15  miles  almost 
due  west  from  the  body  of  the  plateau  ;  but  the  later  formations  in- 
volved having  been  greatly  eroded,  the  spur  as  it  now  exists  is  much 
shorter.  Tlrere  is  a  narrow  synclinal  valley  between  it  and  the  main 
fold;  and  a  shorter  more  open  one  between  its  southern  side  and  Sec- 
tion Ridge,  both  of  which  communicate  with  the  open  country  which 
stretches  away  to  the  southward.  The  Section  Ridge  spur  is  some- 
what shorter  than  the  other,  although  the  axial  length  of  this  as 
well  as  of  the  other  is  greater  than  the  breadth,  and  the  direction 
of  its  axis  is  a  little  to  the  south  of  west.  The  strata  involved  in 
these  spurs  dip  regularly  around  the  base  of  each,  and  thence  trend 
away  at  the  base  of  the  plateau  on  the  one  hand,  and  that  of  the 
Uinta  Range  on  the  other.  The  regularly  curved  dip  around  the 
distal  end  of  each  spur  is  so  marked  a  geological  feature  that  I  have 
applied  to  it  the  term  partiversal'  dip. 

The  vertical  displacement  of  Midland  fold  is  less  than  that  of 
Yampa  fold,  so  that  the  Triassic  rocks  occupy  the  greater  part  of  its 
surface,  the  Carboniferous  strata  not  having  been  brought  to  view. 
Its  eastern  terminus  is  by  a  broad  sweeping  dip,  like  that  at  the  east- 

'A  quaquaversal  dip,  as  the  term  is  usually  applied,  is  in  all  directions  from  a 
given  point.  A  partiversal  dip  is  around  the  vanishing  end  of  an  anticlinal  axis. 
The  region  round  about  the  Uinta  Mountain  Range  contains  numerous  examples  of 
partiversal  dip. 


700 


GEOLOGY    OF   NORTHWESTERN    COLORADO. 


em  end  of  Yampa  Plateau  fold,  and  it  retreats  a  little  to  the  west- 
ward, as  the  last  named  fold  does  with  relation  to  the  terminus  of 
the  main  fold. 

The  Dan  forth  Hills,  which  have  already  been  mentioned  as  occu- 
pying a  portion  of  the  eastern  part  of  this  district,  rest  upon  the 
comparatively  gentle  fold,  or  uplift  to  which  I  have  given  the  same 
name.  This  fold  lies  adjacent  to  the  southern  side  of  the  inceptive 
portion  of  the  Uinta  fold  and  within  the  broad  curve  which  it  makes 

in  its  extension  from  the  Uinta  to  the 
Park  Range.  Its  lateral  position  with 
relation  to  the  inceptive  fold  is  indi- 
cated by  the  section,  Fig.  60. 

These  subordinate  folds  have  been 
briefly  described  here  that  they  may 
be  referred  to  in  connection  with  the 
discussions  yet  to  be  made.  Let  us 
now  return  to  the  eastern  terminus  of 
the  main  portion  of  the  Uinta  fold 
.•iiid  proceed  eastward  along  its  in- 
ceptive portion.  The  axis  of  this 
portion  of  the  fold  passes  along  the 
broad  valley  which  I  have  called 
Axial  Basin,  and  thence  by  a  broud 
curve  to  the  northeastern  base  of  the 
White  River  plateau  which  is  a  spur 
of  the  Park  Range.  It  is  not  a  con- 
spicuous geological  feature,  but  the 
reality  of  its  existence  is  plainly  ap- 
parent on  investigation.  Its  vertical 
displacement,  although  considerable, 
is  comparatively  slight ;  and  the  strata 
involved  are,  in  Axial  Basin,  partly 
covered  from  view  by  those  of  the 
Brown's  Park  group.  It  also  becomes 
somewhat  indistinct  at  its  eastern  end 
in  consequence  of  the  confusion  of  dips 
upon  approaching  the  foot  hills  of  the 
Park  Range,  and  of  the  presence  there 
of  basaltic  outflows.  Its  general  char- 
acter is  shown  by  Fig.  CO,  representing 
a  section  across  it  about  five  miles 
eastward  from  Yampa  Mountain. 
Upon  this  inceptive  portion  of  the  Uinta  fold  there  have  been 
imposed  two  extraordinary  geological  features,  namely,  the  June- 


WHITE.] JUNCTION    MOUNTAIN    UPTHRUST.  701 

tion  and  Yarapa  Mountain  upthrusts,1  which  I  regard  as  the  result 
of  localization,  or  a  locally  intensified  application  of  the  force  by 
which  the  fold  was  elevated,  and  which  will  now  be  considered. 

JUNCTION    MOUNTAIN    UPTHRUST. 

Going  only  two  or  three  miles  eastward  from  the  eastern  terminus 
of  the  main  fold,  where  we  have  seen  the  later  formations  dip  so  sud- 
denly from  view,  we  come  to  the  western  border  of  Junction  Mountain 
up  thrust.  Here  we  find  the  same  strata  rise  again,  even  more  suddenly 
than  they  disappeared  ;  and  we  also  find  that  the  formations  of  Pale- 
ozoic age,  which  constitute  the  high  mountain  peaks  of  the  Uinta 
Range  only  a  few  miles  away,  are  here  again  uplifted,  not  only  to  the 
surface  of  the  low  land  around  the  mountain,  but  to  a  maximum 
height  of  nearly  2,000  feet  above  it.  The  strata  involved  in  this  uplift 
(which,  because  of  its  sharply  defined  limits,  and  of  the  extent  of  ver- 
tical displacement  of  those  strata,  I  have  called  an  up  thrust),  occupy 
an  elongate  oval  area  the  extreme  longer  diameter  of  which  is  nearly 
12  miles,  and  the  shorter  about  4  miles.  The  direction  of*  the  longer 
diameter,  being  approximately  northwest  and  southeast,  is  obliquely 
transverse  to  the  general  trend  of  the  axis  of  the  main  fold.  In  this 
respect,  as  well  as  by  the  peculiar  character  of  displacement  of  the 
strata  involved,  the  isolation  of  this  upthrust  is  quite  complete, 
although  it  lies  so  near  the  terminus  of  the  main  portion  of  the 
Uinta  fold  and  upon  the  axis  of  its  inceptive  portion. 

So  sharply  have  the  strata  been  uplifted  in  this  displacement  that 
they  are  either  faulted  or  are  nearly  or  quite  vertical  at  a  portion  of 
each  side  of  the  upthrust ;  and  they  also  dip  very  abruptly  at  other 
portions,  and  around  its  ends.  The  Mesozoic  formations  through 
which  the  older  ones  were  forced  lie  around  the  mountain,  but  im- 
mediately adjacent  to  it  they  are  largely  covered  from  view  by  the 
strata  of  the  Brown's  Park  group,  which  lie  unconformably  upon 
them.  The  disturbance  which  those  Mesozoic  formations  have  suf- 
fered in  that  neighborhood  beyond  the  base  of  the  mountain  is  so 
slight  that  one  can  not  recognize  it  as  having  been  connected  with 
the  upthrust  movement.  That  is,  their  position  as  marking  the 
presence  of  the  inceptive  fold  and  certain  subordinate  uplifts  does 
not  seem  to  have  been  changed  by  the  localized  upthrust  movement. 

1  In  using  the  terms  "  uplift "  and  "  upthrust,"  I  do  not  ordinarily  intend  to  ex- 
press an  opinion  as  to  the  actual  direction  of  the  movements  by  which  the  strata 
were  displaced  ;  but  in  describing  displacements  it  seems  to  be  more  natural  to  as- 
sume that  the  lower  mass,  which  is  the  larger,  was  the  fixed  one ;  and  that  the 
higher,  which  is  relatively  the  smaller,  was  uplifted.  The  former  term  needs  no 
explanation  in  such  a  connection.  The  latter  term  is  peculiarly  applicable  to  the 
character  of  the  displacements  by  which  Junction  and  Yampa  Mountains  are  char- 
acterized, as  will  appear  in  connection  with  their  description. 


702  OEOLOGY    OF    NORTHWESTERN    COLORADO. 

The  Mesozoic  formations  which  must  necessarily  have  risen  upon 
the  top  of  the  older  ones  within  the  upthrust  area  have  been  re- 
moved by  erosion  as  has  also  a  large  part  of  the  full  thickness  of 
the  Carboniferous  strata  which  came  up  beneath  them.  Therefore, 
only  strata  of  Paleozoic  age  now  enter  into  the  structure  of  the 
mountain  proper,  while  the  upturned  edges  of  the  later  ones,  where 
they  have  not  been  sharply  severed  by  faulting,  lie  around  its  base. 

YAMPA   MOUNTAIN    UPTHRUST. 

Going  from  Junction  Mountain  about  10  miles,  along  the  axis  of 
the  inceptive  fold,  we  pass  all  the  way  over  the  low  lands  of  Axial 
Basin,  the  surface  of  which  is  there  mostly  occupied  by  the  Brown's 
Park  group,  and  reach  Yampa  Mountain,  which  rises  directly  upon 
that  axis,  as  does  Junction  Mountain.  Here  wo  find  that  the  descrip- 
tion which  has  just  been  given  of  the  Junction  Mountain  upthrust 
will  apply  in  all  essential  respects  to  this.  All  around  the  base  of 
Yampa  Mountain  the  strata  of  the  Brown's  Park  group  cover  the 
immediate  borders  of  this  upthrust,  even  to  a  greater  extent  than 
they  do  those  of  Junction  Mountain  upthrust ;  but  it  is  readily  seen 
that  the  two  mountains  are  essentially  identical  in  structure  and 
character,  and  that  they  have  been  produced  in  a  similar  manner. 
Yampa  upthrust,  however,  is  smaller  than  the  other,  and  it  is  also 
much  farther  away  from  any  other  much-displaced  strata.  Its  out- 
line is  oval,  the  longer  diameter,  including  all  the  strata  involved, 
not  much  exceeding  seven  miles  in  length,  and  its  shorter  diameter 
is  less  than  four  miles.  The  longer  diameter  is  nearly  at  right  angles 
with  that  of  Junction  Mountain  upthrust,  and  it  is  nearly  transverse 
with  the  inceptive  portion  of  the  Uinta  axis,  tipon  which  it  rises. 
The  relation  of  these  two  upthrusts  to  each  other,  and  to  the  main 
and  inceptive  portions  of  the  Uinta  fold,  is  indicated  by  the  section, 
Fig.  61. 

The  amount  of  vertical  displacement  is  about  the  same  in  each  of 
these  upthrusts,  the  extent  of  which  is  estimated  from  the  thickness 
of  the  formations  as  given  in  the  foregoing  table,  and  from  the  con- 
tour lines  on  the  published  topographic  maps  of  that  region.  The 
contour  line  which  cuts  the  top  of  the  Uinta  Quartzite  in  both  these 
mountains  passes  along  the  southern  side  of  Axial  Basin  approxi- 
mately at  the  base  of  the  Laramie  and  top  of  the  Fox  Hills  group. 
Referring  to  the  preceding  table  we  find  the  thickness  of  the  inter- 
vening formations  to  be  11,800  feet.  It  is  plain,  therefore,  that  the 
amount  of  vertical  displacement  in  both  these  mountains  is  not  less 
than  is  represented  by  those  figures.'  That  is,  within  the  narrow 

1  The  estimate  of  8,000  feet  given  in  my  report  on  that  region  (  loo.  cit.)  was  in- 
advertantly made  too  small,  as  may  be  seen  by  the  data  there  used,  as  well  as  by  the 
figures  in  the  preceding  table. 


WHITE.] 


YAMTA    MOUNTAIN    UPTHKUST. 


703 


and  sharply  defined  limits  that  have  been 
described,  the  strata  of  which  both  these 
mountains  are  composed  have  been  thrust 
up  a  vertical  distance  of  more  than  two 
miles ;  which,  in  the  case  of  the  Yampa 
upthrust,  is  nearly  equal  to  one-third  the 
longer  diameter  of  the  area  affected  by  it. 

As  indicating  that  the  amount  of  vertical 
displacement  in  these  upthrusts  is  really 
greater  than  has  been  mentioned,  it  may  be 
stated  that  the  Fox  Hills  and  Laramie  strata 
referred  to  have  themselves  been  elevated 
to  a  considerable  extent  in  the  adjacent  Dan- 
forth  Hills  uplift,  as  shown  by  the  section, 
Fig.  (JO.  This  figure  will  also  serve  to  illus- 
trate the  relation  of  the  Yampa  upthrust 
to  the  inceptive  fold,  and  to  the  adjacent 
Danforth  Hills  uplift.  That  is,  if  within 
the  space  indicated  by  the  length  of  the  line 
x,  x,  the  strata  should  be  elevated  until  the 
base  of  the  carboniferous  series  reaches  the 
place  of  the  uppermost  dotted  line,  the  ver- 
tical extent  and  lateral  restriction  of  the 
Yampa  upthrust  will  be  indicated. 

RELATION    OF  THE  UINTA    FOLD    TO     OTHER 
FOLDS  AND  TO  THE  PARK  RANGE  UPLIFT. 

It  is  true  that  the  vertical  displacement 
in  the  case  of  the  two  upthrusts  is  much 
less  in  amount  than  is  that  of  the  great  fold  ; 
but  the  amount  of  displacement  is  far  more 
remarkable  in  the  case  of  the  upthrusts  than 
it  is  in  the  case  of  the  fold,  because  of  the 
very  narrow  limits  within  which  the  dis- 
placements in  the  former  case  have  taken 
place.  The  narrow  and  sharply  defined 
limits  of  these  upthrusts,  and  the  severing 
of  the  displaced  portions  of  the  formations 
from  the  great  mass  of  each  respectively, 
with  little  or  no  general  disturbance  of  the 
latter  beyond  those  limits,  may  be  compared 
to  the  action  of  a  large  punch  on  being 
forced  by  great  power  through  a  number 
of  thick  iron  plates.  The  comparison  will 
be  more  complete  if  we  conceive  that  the 
cutting  border  of  such  a  punch  had  become 


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GEOLOGY    OF    NORTHWESTERN    COLORADO. 


dulled  at  certain  places  so  that  a  part  of  the  iron  through  which  it 
was  being  forced  would  drag,  and  not  be  sharply  severed.  Portions 
of  the  uplifted  strata  at  the  base  of  both  these  mountains  seem  to 
have  thus  dragged  during  their  elevation,  while  other  portions  were 
sharply  severed  as  if  the  displacement  had  really  been  done  by  a  huge 
punch  acting  from  beneath  ;  producing,  of  course,  an  ordinary  fault 
there. 

Referring  to  the  fact  that  the  two  upthrusts  have  taken  place  upon 
the  axis  of  the  inceptive  portion  of  Uinta  fold,  and  apparently  after 
that  portion  had  reached  its  present  stage,  it;  is  well  to  turn  aside  for 
the  moment  to  notice  further  certain  other  phenomena  which  are 
correlated  with  this,  and  to  consider  their  probable  significance. 
The  phenomena  referred  to  indicate  that  while  the  displacements 
now  observable  in  that  region  were  in  progress  there  were  many 
local  arrests  and  accelerations  of  the  elevating  movement  which  pro- 
duced a  final  diversity  among  them  that  did  not  exist  in  their  incep- 
tion. For  example,  the  present  structural  condition  of  the  .Uinta 
fold  seems  to  warrant  the  assumption  that  it  was  once,  along  its 
entire  length,  in  the  condition  in  which  the  inceptive  portion  now 
is*  except  for  the  presence  of  the  .two  upthrusts ;  furthermore,  that 
these  upthrusts,  as  well  as  the  main  portion  of  the  fold,  continued 
their  upward  progress  while  what  I  call  the  inceptive  portion  re- 
mained as  it  was  when  its  elevation  was  arrested. 

Again,  it  may  be  assumed  that  the  subordinate  folds  adjacent  to 
the  eastern  end  of  the  main  Uinta  fold  all  had  an  approximately  equal 
start  with  the  latter,  but  that  the  final  extent  of  the  upward  move- 
ment was  different  in  each  case.  For  example,  when  the  Midland 
fold  ceased  to  rise  the  elevation  of  the  others  continued.  Then  the 
rise  of  Yam  pa  Plateau  fold  ceased,  while  that  of  the  great  fold  con- 
tinued until  its  completion.  These  successive  steps  are  well  indi- 
cated in  the  section,  Fig. '59. 

The  elevating  force  was  not  only  strangely  concentrated  in  the 
case  of  the  two  upthrusts,  but  it  seems  to  have  been  applied  in  an 
unusual  manner,  especially  when  we  consider  the  position  of  the 
longer  axis  of  each  with  relation  to  that  of  the  other,  and  also  to 
that  of  the  Uinta  fold.  It  has  been  mentioned  that  the  direction  of 
the  longer  axis  of  the  Junction  upthrust  is  northeasterly  and  south- 
westerly. Viewing  these  upthrusts  only  in  relation  to  the  Uinta  fold 
proper,  and  regarding  them  as  nearly  or  quite  isolated  portions  of  the 
same,  one  would  naturally  expect  to  find  their  longer  axes  coinciding 
with  a  line  projected  from  the  axis  of  the  main  fold,  and  he  would  also 
expect  to  find  the  intervening  strata  along  that  line  to  have  partaken 
largely  in  the  upward  movement.  That  is,  in  view  of  the  simplicity 
of  the  main  portion  of  the  Uinta  fold  one  might  naturally  expect  to  find 
evidence  that  the  uplifting  force  which  was  applied  along  its  entire 
axis  would  have  acted  with  approximate  uniformity.  But  the  fore- 


WHITE.]  RELATION    OF   THE    PARK    AND    UINTA    RANGES.  705 

going  statements  show  that  neither  of  the  axes  of  the  two  upthrusts 
coincide  with  such  a  line  or  with  each  other.  Also,  that  only  a 
slight  elevation  of  the  strata  has  occurred  along  the  inceptive  portion 
of  the  Uiuta  fold,  as  compared  with  that  of  the  main  portion  and 
with  the  upthrusts. 

While  the  Danforth  Hills  uplift  holds  an  intermediary  relation  to 
both  the  Uinta  and  Park  ranges,  it  seems  natural  to  regard  the  two 
upthrust  mountains  as  outlying  members  of  the  Uinta  Range,  and 
there  also  seems  to  be  no  sufficient  ground  for  doubt  that  both  up- 
thrusts  were  produced  as  a  part  of  the  orogenic  movements  which 
resulted  in  the  final  completion  of  the  Uinta  fold.  Still,  the  relative 
position  and  the  peculiarities  of  these  upthrusts  are  such  that  it  is 
evident  they  ought  to  be  studied,  not  with  reference  to  that  fold 
alone,  but  also  with  reference  to  the  Park  Range  of  the  Rocky 
Mountain  system.  Such  a  study  not  only  reveals  the  existence  of 
an  intimate  relationship  between  the  two  great  ranges,  but  it  dis- 
covers evidence  that  both  of  them,  together  with  their  subordiiia'e 
folds,  their  spurs,  and  the  two  upthrust  mountains,  are  all  the  re- 
sults of  one  great  system  of  orogenic  movements. 

A  part  of  the  facts  showing  the  relationship  of  the  Uinta  to  the 
Park  Range  has  already  been  mentioned,  and  in  support  of  this 
view  the  following  remarks  may  be  added  :  A  large  irregular  spur 
of  the  Park  Range,  known  as  the  White  River  Plateau,  reaches 
within  the  limits  of  this  district.  In  this  plateau,  a  large  part  of 
which  is  shown  on  the  lower  right  hand  portion  of  the  accompanying 
map,  the  Carboniferous  rocks  are  brought  to  view  as  they  are  in  the 
Uinta  Range  and  in  the  two  upthrusts.  Along  its  western  base  also 
the  same  Mesozoic  formations  which  are  upturned  at  the  base  of 
the  Uinta  Mountains  are  there  upturned,  and  their  outcrop  thus 
formed  extends  far  southward  along  the  western  flank  of  the  Park 
Range.  The  Fox  Hills  and  Laramie  strata  thus  upturned  constitute 
what  is  known  as  the  Great  Hogback. 

A  part  of  these  formations,  less  abruptly  upturned,  may  be  traced 
by  a  broad  curve  continuously  across  the  intervening  space  between 
the  two  ranges  from  the  western  base  of  the  White  River  Plateau  to 
the  southern  base  of  the  accessory  folds  of  the  Uinta  Range.  The 
general  trend  of  these  upturned  formations  approximately  corre- 
sponds with  that  of  the  inceptive  portion  of  the  Uinta  axis,  but  it  is 
somewhat  modified  by  the  presence  of  the  Danforth  Hills  uplift. 
Their  dip  also  corresponds  with  the  comparatively  gentle  elevation 
of  the  inceptive  fold,  and  there  is  almost  nowhere  any  indication 
that  either  the  dip  or  trend  has  been  affected  by  either  of  the  two 
upthrusts. 

With  the  two  great  mountain  folds  rising  by  simultaneous  stages 
at  right  angles  with  each  other  and  serving  as  ponderous  buttresses 
on  either  hand,  it  is  not  strange  that  any  elevating  force  which  may 
9  GEOL 45 


706  GEOLOGY    OF    NOKTHWESTEKN    COLORADO. 

have  been  exerted  along  and  at  either  end  of  the  intervening  space 
should  have  been  diversely,  if  not  abnormally  applied.  The  results 
of  this  diversity  in  the  application  of  elevating  force  are  conspicu- 
ously seen  in  the  extraordinary  cases  of  its  local  restriction  ;  in  the 
diverse  positions  of  the  resulting  subordinate  axes,  and  in  the  vary- 
ing heights  to  which  closely  adjacent  vertical  displacements  have 
reached,  all  of  which  have  been  discussed  on  preceding  pages.  An 
explanation  of  the  mode  of  origin  of  these  phenomena  ought  doubt- 
less to  be  sought  in  connection  with  studies  in  dynamic  geology,  to 
complete  which  would  lead  the  investigator  far  beyond  the  limits  of 
the  district  specially  considered  in  this  article. 

CANONS  TRAVERSING  THE  UPTHRUSTS  AND  FOLDS. 

The  phenomena  described  on  the  preceding  pages  are  certainly  of 
great  interest,  and  a  part  of  them  are  very  remarkable  ;  but  Some  of 
those  which  are  now  to  be  described,  and  which  pertain  to  the  sec- 
ond of  the  categories  mentioned  in  the  opening  paragraph  of  this 
article,  are,  if  possible,  still  more  remarkable.  Those  now  to  be  con- 
sidered have  reference  to  the  corrasion  of  the  valleys  and  cafions  of 
the  rivers  which  traverse  the  same  region,  and  a  part  of  which  cut 
through  the  uplifts  that  have  been  described. 

To  most  persons  it  would  seem  natural  to  infer  that  the  rivers 
which  traverse  a  mountain  region  would  flow  through  the  low  lands, 
avoid  the  mountains,  and  pass  around  the  end  of  the  ranges  rather 
than  through  them.  This  region,  however,  presents  remarkable 
examples  of  an  entirely  different  character ;  that  is,  the  principal 
rivers  here  flow  in  narrow  canons  along  a  part  of  their  course,  which 
they  have  themselves  evidently  cut.  Not  only  is  the  eastern  portion 
of  the  Uinta  Mountain  Range  traversed  in  different  directions  by 
such  canons,  with  the  rivers  at  the  bottom,  but  isolated  mountains 
surrounded  by  low  lands  are  similarly  traversed  in  the  same  region. 
Even  when  taking  into  consideration  the  geological  structure  of  a 
region,  it  would  not  seem  unnatural  to  suppose  that  the  rivers  woidd 
generally  be  found  to  run  in  synclinal  valleys  between  such  folds  of 
the  strata  as  may  have  been  elevated  in  their  vicinity.  It  is  true 
that  a  river  within  this  region  is  sometimes  found  to  occupy  a  syn- 
clinal valley  for  a  short  distance ;  but  such  cases  are  rare,  while  we 
find  numerous  examples  of  rivers  traversing  such  elevated  folds  as 
have  been  described.  Indeed,  these  rivers  traverse  the  folds  in  such 
directions,  and  occupy  such  positions  in  relation  to  them,  as  to  show 
that  the  folds  have  exerted  little  or  no  appreciable  influence  on  the 
location  of  the  rivers. '  . 

1  All  the  various  conditions  of  drainage  with  its  relation  to  the  underlying  geological 
structure,  which  occur  in  this  region,  have  been  fully  described  and  discussed  by 
Powell  in  his  Exploration  of  the  Cafion  of  the  Colorado,  pp.  160  to  166,  to  which  the 
reader  is  referred. 


WHITE.]  CANOtfS    OF    YAMPA    AND    GKKKX    HIVKKS.  707 

The  streams  which  drain  this  district,  as  before  mentioned,  are 
Green,  Yampa,  Snake,  and  White  Rivers,  the  latter  traversing  only 
a  portion  of  its  southern  border.  After  leaving  the  foot-hills  of  the 
Park  Range,  White  River  reaches  its  confluence  with  the  Green 
without  having  cut  any  important  canons  in  either  the  Great  Hog- 
back or  the  Raven  Park  fold,  both  of  which  uplifts  it  traverses.  It 
has,  however,  cut  some  interesting  canons  through  the  Tertiary  strata 
along  other  portions  of  its  course ;  but  as  these  are  of  somewhat  dif- 
ferent character  from  those  to  which  I  shall  especially  refer  they 
need  not  now  be  discussed. 

Snake  River,  after  receiving  the  waters  of  its  main  tributaries 
from  the  foot-hills  of  the  Park  Range,  flows  southwestwardly  through 
comparatively  open  country  to  its  confluence  with  the  Yampa  with- 
out traversing  any  conspicuous  uplift  of  the  underlying  strata  in  its 
course.  It  even  passes  closely  around  the  northern  end  of  Junction 
Mountain  and  reaches  its  confluence  with  the  Yampa  in  Lily's  Park 
through  the  narrow  strip  of  low  land  (which  is  a  true  synclinal  valley) 
between  that  mountain  and  the  eastern  end  of  the  Uinta  Range.  In 
short,  it  follows  such  a  course  as  those  unacquainted  with  other  con- 
ditions would  naturally  expect  a  river  to  choose.  But  in  this  respect 
Snake  River  is  really  an  exception  to  the  general  rule  which  is  appli- 
cable to  the  other  rivers  that  traverse  this  district,  as  will  be  seen  by 
the  following  remarks  on  the  canons  of  Green  and  Yampa  Rivers. 

It  is  true  that  the  course  of  both  Green  and  Yampa  Rivers  is  in 
large  part  through  open  country,  or  through  lands  that  are  not  • 
mountainous,  where  they  have  had  only  the  later  and  softer  forma- 
tions through  which  to  cut  their  way.  But  while  peacefully  flowing 
along  such  portions  of  their  course  they  often  strangely  leave  these 
seemingly  favorable  positions  to  traverse  mountains  or  other  eleva- 
tions which  in  most  cases  are  composed  of  harder  strata  than  those 
over  which  the  rivers  had  previously  been  flowing.  In  traversing 
these  mountains  also  they  almost  invariably  do  it  by  narrow  canon: 
the  walls  of  which  are  often  nearly  or  quite  perpendicular,  and  of 
great  height. 

THE   UINTA   CANONS   OF   GREEN   RIVER. 

Green  River  flows  southward  through  the  central  portion  of  the  ' 
Green  River  Basin,  towards  the  eastern  portion  of  the  Uinta  Range 
of -mountains  which  lies  directly  across  the  river's  course.  Upon 
reaching  the  foot-hills  the  river  at  once  passes  through  them  and 
enters  the  northern  side  of  the  range.  Here,  after  making  a  sharp 
bend  in  what  is  called  Horseshoe  Cafion,  as  if  it  were  about  to  return 
upon  itself,  it  sweeps  by  another  bend  further  into  the  range  and  pur- 
sues its  course  for  a  long  distance  through  deep,  narrow  canons.  Af- 
ter the  river  has  reached  well  within  the  range  it  turns  suddenly  cast  - 
ward,  its  course  now  being  through  Red  Canon,  which  lies  nearly 


708  GEOLOGY    OF    NORTHWESTERN    COLORADO. 

parallel  with  the  axis  of  the  Uiiita  fold.  From  this  canon  it  emerges 
into  Brown's  Park,  the  low  lands  of  which  it  traverses  for  a  distance 
of  about  25  miles,  its  general  course  there  being  a  little  to  the  south 
of  east.  A  less  distance  farther  in  that  direction  would  have  carried 
it  over  similar  low  lands  to  the  eastern  terminus  of  the  Uinta 
Range,  around  which,  and  then  southward,  the  low  lands  continue. 
Instead  of  availing  itself  of  this  seemingly  favorable  route  to  reach 
the  southern  side  of  the  Uinta  Range,  where  lies  its  destined  course, 
the  river  leaves  Brown's  Park  at  the  point  indicated,  and  turning 
suddenly  southward  it  re-enters  the  Uinta  Range  by  the  "Gate  of 
Lodore,"  which  is  the  northern  end  of  the  narrow  canon  by  which 
the  river  traverses  the  whole  width  of  the  Uinta  Range.  The  canon 
walls  of  the  Gate  of  Lodore  rise  abruptly  from  the  river  and  from  the 
south  side  of  Brown's  Park,  where  they  are  more  than  2,000  feet  in 
perpendicular  height  above  the  river ;  and  some  of  the  higher  points 
near  and  along  the  course  of  the  caflon  are  fully  1,000  feet  higher. 

After  traversing  the  whole  width  of  the  main  range,  the  river 
emerges  into  the  short,  narrow,  synclinal  valley  between  Split  Moun- 
tain and  the  main  range.  This  valley,  as  has  already  been  shown, 
communicates  with  the  low  lands  which  lie  toward  the  south,  the  di- 
rection in  which  the  river  finally  flows.  But  instead  of  pursuing  its 
way  by  this  apparently  favorable  route  the  river  enters  Split  Mount- 
ain, cutting  entirely  through  it,  and  leaving  its  cafion  walls  of  hard 
rock  towering  on  either  hand  to  the  dizzy  height  of  nearly  half  a  mile. 
Then,  and  not  till  then,  does  the  wayward  river  consent  to  go  on  its 
quiet  course  through  the  open  country  towards  its  junction  with 
Grand  River,  where  its  waters,  mingled  with  those  of  that  river  to 
form  the  Colorado,  flow  through  still  more  profound  and  remarkable 
caQous  beyond. 

YAMPA   MOUNTAIN   CANON. 

The  course  of  Green  River  across  the  upfolded  Uinta  Range,  which 
consists  there  wholly  of  the  hard  strata  of  the  Paleozoic  formations, 
when  apparently  it  might  so  easily  have  gone  around  it  upon  low 
lands  and  have  made  its  channel  through  softer  formations,  is  so  re- 
markable as  to  arrest  the  attention  of  every  observer.  But  the 
Yampa  is  perhaps  the  most  remarkable  of  all  the  rivers  in  that 
region  with  reference  to  their  seeming  disregard  of  favoring  condi- 
tions of  location.  This  river  rises  by  numerous  tributaries  among 
the  mountains  of  the  Park  Range,  where  it  has  a  turbulent  course 
of  many  miles  through  rocky  defiles  and  narrow  valleys.  Then 
emerging  from  the  foot-hills  of  the  range,  it  traverses  the  open 
country  which  lies  toward  the  west,  its  general  direction  being 
toward  the  eastern  end  of  the  Uinta  Range  and  along  the  greater 
part  of  the  length  of  Axial  Basin.  This  latter  part  of  its  course; 
being  approximately  upon  the  axis  of  the  inceptive  portion  of  the 


WHITE.]  CANONS    OF    YAMPA    AND    JUNCTION    MOUNTAINS.  709 

Uinta  fold,  Yampa  and  Junction  Mountains  lie  directly  in  its  way, 
while  around  these  mountains  lie  the  low  lands  already  described. 

Upon  reaching  Yampa  Mountain,  the  river,  in  almost  seeming 
wantonness,  cuts  its  way  by  a  short  canon  through  the  hard  Paleo- 
zoic rocks  which  form  the  northern  flank  of  the  mountain,  making 
a  small  bend  into  its  mass,  instead  of  swerving  a  little  in  the  other 
direction  and  passing  at  its  northern  side  upon  the  low  land  there. 
This  canon,  compared  with  others  in  that  region,  is  insignificant,  for 
it  is  very  short  and  its  walls  are  only  from  000  to  800  feet  in  maxi- 
mum height  above  the  adjacent  low  lands  ;  but  considered  in  con- 
nection with  the  geological  structure  beneath,  it  is  very  remarkable. 

JUNCTION   MOUNTAIN   CANON. 

From  Yampa  Mountain  the  river  flows  quietly  over  the  low  lands 
of  Axial  Basin  to  Junction  Mountain,  which  it  cuts  through  in  a 
similar  manner.  As  one  stands  upon  Junction  Mountain  and  looks 
out  over  the  broad  low  land  which  lies  adjacent  to  its  northeastern 
side  and  is  continuous  with  Axial  Basin  toward  the  east  and  with 
Brown's  Park  toward  the  west,  the  opportunity  seems  especially  fa- 
vorable for  the  Yampa  to  have  reached  the  further  side  of  Junction 
Mountain  by  joining  Snake  River  near  the  northern  end  of  the  mount- 
ain. Indeed,  for  more  than  half  its  course  after  leaving  Yampa 
Mountain  the  river  trends  in  that  direction  as  if  it  were  destined  to 
go  there  ;  but  instead  of  doing  so,  it  makes  a  distinct  bend  .south- 
westward,  goes  direct  to  Junction  Mountain  and  cuts  off  its  south- 
ern end,  as  it  had  already  cut  off  the  northern  end  of  Yampa 
Mountain.  The  strata  of  hard  rock,  which  are  upturned  like  a 
broken  dam  at  the  foot  of  the  steep  mountain  side,  constitute  no  im- 
pediment to  the  course  of  the  river,  and  without  swerving  to  the  right 
or  left  it  enters  the  mountain  and  traverses  it  by  a  narrow  canon, 
thr  almost  perpendicular  walls  of  which  reach  a  maximum  height  of 
from  1,000  to  1,200  feet  above  the  low  land  at  either  end  of  the  canon. 

YAMPA   CANON. 

After  having  traversed  Junction  Mountain,  the  river  has  a  peaceful 
course  of  eight  or  ten  miles  through  Lily's  Park,  which  is  merely  a 
broadening  of  the  valley,  where  it  receives  the  waters  of  Snake 
River.  Then,  instead  of  joining  Green  River  by  way  of  the  low 
land  at  either  the  northern  or  southern  side  of  the  Uinta  Range,  it 
boldly  enters  its  eastern  end,  crossing  the  upturned  strata  there  as  it 
had  done  in  the  former  cases.  From  here  the  remainder  of  the 
river's  course  is  through  a  narrow  caSon,  which,  for  a  large  part  of  its 
length,  is  fully  1,200  feet  deep,  and  which  joins  the  cafion  of  Green 
River  before  the  latter  emerges  from  the  southern  side  of  the  range. 


710  GEOLOGY    OF    NORTHWKSTKUN    COLOIJA  Do. 

The  distance  from  end  to  end  of  Yampa  Canon,  in  a  straight  line, 
is  about  twenty  miles.  While  it  meanders  to  some  'extent,  its  gen- 
eral course  is  direct,  and  coincides  approximately  with  the  axis  of 
the  Uinta  fold.  That  is,  the  narrow  canon  has  been  cut  perpen- 
dicularly into,  and  mainly  along  the  strike  of,  the  hard  Carbonifer- 
ous strata,  where  they  have  their  southerly  dip  in  the  southern  flank 
of  that  fold.  In  short,  the  position  and  direction  of  the  river  are 
such  with  relation  to  the  dip  and  trend  of  the  strata  there  that  no 
indication  is  apparent  that  the  latter  have  had  any  influence  in  de- 
termining the  former. 

CONCLUDING  REMARKS. 

If  the  phenomena  relating  to  the  river  canons  of  this  district 
which  have  just  been  described  were  considered  without  reference 
to,  or  any  knowledge  of,  a  geological  history  of  the  region  in  which 
they  occur,  they  would  be  wholly  inexplicable  ;  but  considered  with 
reference  to  that  history,  their  origin  is  easily  explainable.  And 
yet,  with  all  the  relevant  facts  in  mind,  even  he  who  is  accustomed 
to  weigh  and  consider  such  evidence  is  often  amazed  at  the  results 
which  have  been  produced  by  the  forces  which  are  arid  have  always 
been  in  constant  operation  upon  the  face  of  the  earth. 

The  following  summary  statement  of  -the  origin  of  these  phenom- 
ena is  given  in  a  few  words,  but  a  careful  examination  of  Powell's 
elaborate  statement  of  the  subject  (op.  cit.),  should  not  be  omitted.' 
The  rivers  of  the  region  occupied  the  surface  before  it  was  elevated 
to  any  considerable  height  above  the  level  of  the  sea,  and  before  the 
region  was  greatly  disturbed  by  orogenic  movements.  When  the 
uplifts  were  formed  in  which  the  mountains  originated,  the  rivers 
refused  to  yield  "the  right  of  way."2  That  is,  the  rivers  were 

1  This  subject  is  also  well  stated  by  Button  in  the  Second  Ann.  Rep.  of  the 
Director  of  the  U.  S.  Geol.  Survey,  pp.  «Mi:i. 

8  The  theory  is  entertained  by  some  geologists  that  the  later  formations  completely 
mantled  the  whole  region  after  the  great  displacements  which  have  been  de- 
scribed occurred,  and  after  resulting  mountains  and  other  great  topographic  features 
were  produced.  Further,  that  the  present  drainage  system  was  established  upon 
the  surface  of  those  later  formations,  and  that  the  streams  have  dropped  to  their 
present  levels  as  the  surface  of  the  region  gradually  became  degraded  by  erosion. 
Such  a  theory  requires — 

(1)  That  the  present  drainage  system  of  which  the  Colorado  is  the  principal  chan- 
nel was  established  after  the  close  of  the  Tertiary  period. 

(2)  That  this  system  was  established  upon  a  land  surface  the  lower  portions  of 
which  were  then  at  an  elevation  little  if  any  less  than  10,000  feet  above  the  level  of 
the  sea,  a  large  part  of  it  at  a  still  greater  elevation. 

(8)  That  to  give  the  requisite  amount  of  drainage  water  to  produce  the  vast  erosion 
and  corrasion  which  have  taken  place  there,  the  geographical  extent  of  that  greatly 
elevated  region  must  have  been  quite  equal  to  that  which  is  now  drained  by  Green 
River  and  its  tributaries. 

The  possibility  that  such  conditions  could  have  existed  seems  inadmissable. 


WHITE.]  ORIGINAL    OF    THE    CANONS.  711 

established  in  a  large,  comparatively  plain  region,  which  they 
drained,  their  location  having  been  determined  by  conditions  then 
prevailing.  Subsequently,  movements  of  the  earth's  crust  took 
place  in  the  same  region,  resulting  in  broad  elevations  and  in 
elongate  folds  and  locally  restricted  uplifts,  the  material  of  which, 
after  great  erosion,  became  respectively  the  high  plateaus,  mount- 
ain ranges,  and  isolated  mountains  or  mountain  clusters  which  now 
exist.  When  the  later  part  of  the  elevation  of  the  great  Plateau 
Province  took  place  its  pre-existing  drainage  system  was  necessarily 
raised  witli  it  to  some  extent,  so  that  their  river  beds  are  now  at  a 
higher  level  above  the  sea  than  they  originally  were.  But  this 
elevation  of  the  river  beds  has  been  little  as  'compared  with  that  of 
the  present  land  surface,  and  especially  so  if  compared  with  the 
amount  of  vertical  displacement  that  has  taken  place  there  since  the 
rivers  were  first  established,  because  the  rivers  have  maintained  a 
comparatively  low  level  for  their  beds  by  cutting  deep  canons  in  the 
rising  land. 

When  a  fold  like  that  of  the  Uinta  Range,  for  example,  began  its 
elevation  across  or  along  the  course  of  one  of  these  rivers,  the  cor- 
rasive  action  of  the  latter  was  immediately  exerted  upon  the  threat- 
ened obstruction,  and  overcame  it  regardless  of  the  hardness  of  the 
uplifted  rock,  and  this  action  did  not  cease  or  fail  in  its'  effect  as 
long  as  the  elevation  continued.  This  corrasive  action  of  rivers  is, 
indeed,  very  slow ;  so  also  has  been  the  movement  of  elevation,  the 
one  having  balanced  the  other  even  through  thousands  of  feet  of 
vertical  elevation  of  the  underlying  rocks.  In  view  of  the  stupen- 
dous effects  of  the  action  of  these  two  forces  which  may  be  witnessed 
in  the  canons  of  the  region  here  discussed,  and  in  the  still  grander 
canons  of  the  Colorado,  one  becomes  impressed  with  the  immensity 
of  the  results  which  may  be  accomplished  by  slowly  acting  forces 
through  long  periods  of  time. 

Not  only  were  the  rivers  not  checked  in  their  flow  when  mountain 
folds  were  elevated  athwart  their  course,  biit  they  refused  to  be 
thrust  aside  by  such  folds  as  may  have  been  raised  either  directly  or 
partially  beneath  them  with  the  direction  of  their  axes  coinciding 
more  or  less  nearly  with  that  of  the  river's  course.  The  longer 
canon  of  Yampa  River,  upon  the  southern  flank  of  the  Uinta  fold, 
and  Red  Canon  of  Green  River,  upon  its  northern  flank,  are  examples 
of  such  canons  as  have  been  cut  in  a  direction  approximately  parallel 
with  the  axis  of  a  fold  which  has  been  elevated  from  beneath  them, 
while  the  direction  of  Lodore  Canon,  of  the  latter  river,  is  transverse 
to  the  axis  of  the  fold. 

But,  since  these  longer  canons  traverse  broad  folds  and  elevated 
areas,  it  may  be  suggested  that  the  rivers  which  produced  them  were 
less  liable  to  be  swerved  from  their  original  courses  by  the  vertical 
movement  which  took  place  beneath  them  than  they  would  be  in  the 


712  GEOLOGY    OF    NORTHWESTERN    COLORADO. 

case  of  the  rising  of  narrow  folds  and  of  such  upthrusts  as  have  been 
described.  But  the  facts  already  presented  show  that  the  elevation 
of  not  only  the  narrowest  folds,  but  even  that  of  the  two  upthrusts 
which  have  been  described  did  not  cause  the  rivers  under  which  their 
elevation  began  to  swerve  from  their  original  courses  as  the  eleva- 
tion progressed,  to  the  extent  of  more  than  a  few  rods.  This  fact  is 
exemplified  in  Split  Mountain,  where  Green  River  cuts  a  short,  deep 
canon  through  that  prominent  spur  of  Yam  pa  Plateau ;  but  it  is  more 
conspicuously  shown  where  Yampa  River  traverses  both  the  Junction 
and  Yampa  Mountain  upthrusts. 

I  am  sure  that  the  phenomena  described  on  the  foregoing  pages 
merit  the  statement  made  in  the  opening  paragraphs  of  this  article 
that  they  possess  peculiar  interest ;  but,  among  them  all,  none  are 
more  likely  to  permanently  impress  the  reader  than  those  which  are 
Connected  with  the  two  upthrusts  and  the  short  caSous  which  trav* 
erse  them. 


INDEX 


A. 

Agardth,  cited  on  algous  growths  of  hot  springs, 

621. 

Agassiz,  Lake,  exploration  of  basin  of,  11, 12,84,85. 
Alabama,  surveys  in,  3, 54. 

Geologic  work  in,  76. 
Alderson, B.C., work  of,  138,189. 
Aldrich,T.H.,aidby,135. 
Algae   in  hot  springs  of  Yellowstone  National 

Park,  631- j33, 657-685. 
Alkali  salts  in  lakes  of  California  and  Nevada, 

researches  concerning,  89. 
Aluminum,  statistics,  135, 139. 
American  scientific  surveys,  work  on  history  of, 

107. 

Antimony,  statistics,  135, 139. 
Appalachian  Division,  work  of,  12, 13. 
Appalachian  section,  53. 
Archean  geology,  work  of  Division  of,  8-10. 
Archer,  W.,  cited  on  algee  in  hot  springs  of  the 

Azores,  633. 

Arizona,  area  surveyed  in,  3. 
Arkansas,  plant  growths  in  hot  springs  of,  624. 

Surveys  in,  3, 5, 49, 56. 
Asbestus,  statistics,  137, 140. 
Asphaltum,  statistics,  140. 
Atkinson,  W.  R.,work  of, 55. 
Atlantic  Coast  Division,  work  of,  7,8. 
Atlas  sheets  engraved,  5, 6. 

List,  64. 
Azores,  algee  in  hot  springs  of,  633. 

B. 

Baker,  Marcus,  work  of,  50. 
Baldwin,  H .  L. ,  work  of,  56. 
Baring-Gould,  S.,  cited  on  algee  in  hot  springs  of 

Iceland,  623. 

Barnard,  E.  C., work  of, 53. 
Barus,  Carl,  work  of,  141, 143. 
Barytes,  statistics,  1ST,  140. 
Bayley,W.S.,work  of,80,81,83. 
Beals,  W.,  aid  by,  73, 74. 
Becker,  G.  F.,  work  of,  13, 14, 15. 

Report  of,  100-102. 
Berggren,  S..  cited  on  algee  from  hot  springs  of 

New  Zealand,  622. 
Berkley,  J.  M. ,  cited  on  algee  from  hot  springs  of 

Himalayas,  634. 

Cited  on  hot  springs  of  Iceland,  622. 
Berzelius,  C.  R.,  analyses  of  travertine  by,  646. 
Bickmore,  A.  S.,  cited  on  algee  of  hot  springs  in  the 

Celebes,  624. 

Bieu  &  Co.,  engravers,  contracts  with,  5. 
Bien,  J.  R.,work  of,  60,92. 
Bien,  Morris,  work  of,  53. 


Billings,  D.,  cited  on  diatoms  in  waters  of  the 

Mammoth  Hot  Springs,  625. 
Blair. H. B.,  work  of,  56. 
Blake,  James,  cited  on  diatoms  in  water  of  Pueblo 

Hot  Springs,  Nevada,  625. 
Bodfish,  S.  H.,  work  of,  52. 
Borax,  statistics,  137, 139. 
Bradley,  F.  H.,  cited  on  vegetation  of  hot  springs 

of  Yellowstone  National  Park,  625,  626. 
Brewer,  W.  H.,  cited  on  algee  in  hot  springs  of 

California  and  Nevada,  624, 635, 627, 676. 
Brick  and  tile,  statistics,  137. 
Bromine,  statistics,  137,  110. 
Buell,  I.  M.,  work  of,  12,  86. 
Buhrstones,  statistics,  137. 
Building  stone,  statistics,  137. 
Bunsen,  R. ,  cited  on  deposition  of  silica  in  Iceland 

geysers,  656. 
Burns,  Frank,  work  of,  123,  184. 

C. 

California,  algee  in  hot  springs  of,  624. 

Surveys  in,  3,  58. 
California  Division  of  Geology,  work  of,  14, 15,49, 

100-102. 

California  gold  belt,  survey  of,  15. 
Calvin,  Samuel,  acknowledgments  to,  109. 
Cape  Ann,  Massachusetts,  paper  by  N.  S.  Shaler 

on  geology  of,  589-611. 

Carlsbad,  vegetation  in  hot  springs  at,  642.  643. 
Catlett,  Charles,  work  of,  141. 
Cement,  statistics,  137,  139. 
Cenozoic  invertebrate  paleontology,  work  in,  34. 
Cenozoic    invertebrates,    work   of    division   of, 

183-127. 

Central  section  of  geography,  56. 
Chamberlin,  T.  C.,  work  of,  11, 12. 

Report  of,  84-87. 

Charleston  earthquake,  paper  by  Capt.  C.  E.  Dut- 
ton  on,  803-538. 

Lists  of  time  reports,  363-370,  382,383. 

Report  of  observations,  411-528. 
Chatard,T.M.,work  of,  141, 142, 143. 
Chemistry  and  physics,  work  in,  89. 

Work  of  division  of,  141. 
Chromium,  statistics,  135. 
Clark,  E.  B.,  work  of,50. 
Clark,  E.F., aid  by, 76. 
Clark,  W.  B., aid  by,  135. 
Clarke,  F.  W.,  work  of,  89, 98. 

Report  of,  141. 
Coal,  statistics,  138, 139. 
Cobalt  oxide,  statistics,  135, 140. 
Cohn,  F. ,  cited  on  deposition  of  travertine  by  plant 
growth,  621, 627, 642. 

713 


714 


INDEX. 


Coke,  statistics,  136. 

Colorado,  area  surveyed  in,  3. 

Colorado  Division,  work  of,  15. 

Colorado  (northwestern),  paper  by  C.  A.  White  on 
geology  of,  677-712. 

Comstock,  Theodore,  cited  on  vegetation  of  hot 
springs  of  the  Yellowstone  National  Park, 
626. 

Connecticut,  area  surveyed  in,  8. 

Copper,  statistics,  135,  139. 

Corda,  cited  on  algous  growths  in  hot  springs,  621 . 

Correlation  of  geologic  formations,  16. 

Corundum,  statistics,  137, 139. 

Coulter,  John,  cited  on  algae  in  hot  springs  of  Yel- 
lowstone National  Park,  626. 

Cretaceous  and  Tertiary  floras  of  Western  Amer- 
ica, monograph  of  J.  S.  Newberry  on,  25. 

Cretaceous  formations  of  Texas,  study  of  120, 121. 

Cretaceous  formations  of  North  America,  study 
of,  122. 

Cross,  C.  W. ,  work  of ,  88, 89, 91 . 

Curtis,  Josiah,  on  diatoms  in  waters  of  the  Mam- 
moth Hot  Springs,  Yellowstone  National 
Park,  626. 

D. 

Dale, T.N.,  work  of, 75. 
Dall,W.H.,workof,JH. 

Report  of,  123. 

Damour,  analyses  of  siliceous  sinter  by,  670. 
Dana,  J.  D.,  cited  on  algee  from  hot  springs  of 

Luzon,  0*4. 

Dartou,  N.  H.,  work  of,  77,  108. 
Darwin, C.  C.,  report  of,  145-151. 
Davis,  A.  P. ,  work  of,  58. 
Davis,  W.  M.,work  of,  76. 
l)a>is.W.W.,workof,58. 
Day.  David  T. ,  work  of,  26-28. 

Report  of,  134-140. 

Diatom  beds,  Yellowstone  Springs, 668. 
Dikes  of  Cape  Ann,  Massachusetts,  579-583, 589-596. 
Diller,  J.  S.,  work  of.  18, 19, 98, 98-100. 

Report  of,  98-100. 
Disbursements,  U.  S.  Geological  Survey,  abstract 

of,  153-199. 
Disbursing  clerk,  U.  S.  Geological  Survey,  report 

of,  152, 199. 

District  of  Columbia,  area  surveyed  in,  3. 
Douglas,  E.  M.,  work  of.  59. 

Drift  deposits  of  Cape  Ann,  Massachusetts,  547-552. 
Drumlins  of  Cape  Ann,Massachusetts.550,55l. 
Dunnington,  A.  F.,work  of,  58. 
Dutton,  C.  E.,  work  of,  18, 19. 

Report  of,  96-98. 

Paper  on  Charleston  earthquake  by,  203-528. 

E. 

Eakins,  L.  G. ,  work  of,  141 . 

Earthquake  craterlets,  283,  284 

Earthquake  assures,  280-283. 

Earthquake  waves,  velocity  of,  260,  355-389. 

Earthquake  waves  visible  (?>,  264-269. 

Edwards.  A.  M.,  cited  on  animal  and  vegetable  or- 
ganisms in  waters  of  hot  springs  of  Cali- 
fornia, 624, 625. 

Ehrenberg,  cited  on  algse  in  hot  springs,  621. 

Eldridge,  George  H.,  work  of,  90. 


Emerson,  B.  K.,work  of,  75,  76. 
Emmons,  S.  F.,  work  of,  13, 15. 

Report  of,  87-91. 
Engraving,  63. 
Excelsior  Geyser,  eruptions  of,  93, 94. 

F. 

Feldspar,  statistics,  137, 140. 

Financial  statement,  152. 

Fisher,  F.  R.,  account  of  the  Charleston  earth- 
quake by,  242-247. 

Fitch,  C.  H.,  work  of,  57. 5». 

Fletcher,  L.  C. ,  work  of,  53. 

Flint,  statistics,  187, 13!l. 

Flora  of  the  Amboy  Clays  of  New  Jersey,  mono- 
graph of  J.  S.  Newberry  on,  25. 

Florida,  work  in,  73, 74, 126. 

Florida  swamp  lands,  drainage  of,  78, 74. 

Fluorspar,  statistics,  137. 

Foerste,  A.  F.,  work  of,  72. 

Fontaine,  W.  M. ,  work  of,  20, 25, 2(i. 
Report  of,  132, 133. 

Fossil  fishes,  study  of,  25 

Fossil  Fishes  and  Plants  of  the  Triassic  Rocks  of 
New  Jersey  and  the  Connecticut  Valley, 
monograph  of  J.  S.  Newberry  on,  25. 

Fossil  insects,  work  on,  26, 138. 

Fossil  plants,  study  of,  25, 26. 

Fuels,  statistics,  136. 

G. 

Gannett,  Henry,  work  of,  3. 

Report  of,  49-u7. 
Gannett,  S.  S. ,  work  of,  56, 69. 
Gardner,  J.  L. ,  acknowledgments  to,  74, 537. 
Gas  (natural)  in  Indiana,  report  on,  108. 
Gas  (natural),  statistics,  13<i,  139. 
Geiger,  H.R.,work  of, 76, 78. 
Gentry,  J.  W.,  work  of,  119. 
Geography,  report  of  Division  of,  4!>-ti7 
Geologic  work,  progress  in,  7. 
Geology,  paleontology,  and  mineralogy,  record  of 

progress  in,  108. 
Georgia,  surveys  in,  8,  58. 
Geyser  waters,  analyses,  655. 
Gilbert, G.K., work  of,  12, 18, 17, 76. 
Gill,A.C.,aidby,!)2. 
Gill.De  Lancey  W.,work  of,  31.  143. 
Glacial  Division,  work  of,  11,  12,  Hi  N; 
Gold  belt  of  California,  survey  of,  15. 
Gold,  statistics,  145,  139. 
Gooch,  F.  A.,  and  J.  E.  Whitfleld,  analyses  of  hot 

spring  waters  by,  639,  655. 
Goode.R.  U.,work  of,  51, 57. 
Graphite,  statistics,  137. 
Grindstones,  statistics,  187. 
Griswold,W.T.,work  of,52,58 
Gurley, R. R., aid  by,  119. 
Gypsum,  statistics,  137, 189. 

H. 

Hackett,  Merrill,  work  of,  53. 
Hague,  Arnold,  work  of,  15, 16. 

Report  of,  91-96. 
Hall, C.  W., work  of,82,&3. 
Hallock,  William,  work  of,  141,143. 
Hampson,  Thomas,  biographical  sketch  of.  44-46. 


INDEX. 


715 


Hatcher.  J.  B. ,  work  of ,  115. 
Hay,  Robert,  work  of,  104. 
Hayden,  Everett,  aid  by,  309. 
Hayden,  F.  V.,  work  of, 21. 

Biographical  sketch  of,  31-38. 

Cited  on   plant   growth   of   Mammoth  Hot 

Springs,  635. 

Hayes,  C.  W. ,  work  of,  76, 
Hays,  J.  W. ,  work  of,  54. 
Hector,  Dr.  James,  cited  on  siliceous  deposits  of 

New  Zealand  springs,  676. 
Hilgard,  E.  W.,  work  of,  30. 
Hill,  R.T.,  work  of,  98, 117. 
Hillebrand,  W.F.,  work  of,  141, 142. 
Hitlers,  J.  K.,  work  of,  80, 144. 
Himalayas,  algse  in  hot  springs  of,  633, 634. 
Hobbs.  W.  H.,  work  of,  75. 
Hochstetter,  cited  on  hot  springs  of  New  Zealand, 

633. 
Holmes,  W.  H..  work  of,  30. 

Report  of.  143.141. 
Hooker,  William,  cited  on  plants  in  hot  springs  of 

Iceland,  633. 
Hooker,  Dr.  J.  D.,  cited  on  algee  in  hot  springs  of 

the  Himalayas,  633, 637. 
Hot  springs,  plant  growth  in,  613-676 


Iceland,  plants  in  hot  springs  of,  633. 
Iddings,  J.  P.,  work  of,  93, 95. 
Illustrations  Division,  work  of,  30, 143, 144. 
Indiana,  geologic  work  in,  105. 

Report  on  natural  gas  in,  108. 
Infusorial  earth,  statistics,  137. 
Insects,  fossil,  work  on,  36, 133. 
Instruments,  section  for  repair  and  manufacture 

of,  63. 

Invertebrate  paleontology,  work  in,  34. 
Iowa,  surveys  in,  3, 5, 49, 57. 

Geologic  work  in,  106, 107-109. 
Iron,  statistics,  134, 139. 
Irving,  R.  D. ,  work  of ,  10, 11 , 79, 80, 83. 

Biographical  sketch  of,  38-43. 

J. 

Johnson ,  L.  C. ,  work  of ,  30, 109, 1 10. 

Report  of,  110. 
Johnson,  W.  D.,  work  of,  50. 

Joint  planes  of  Cape  Ann,  Massachusetts,  583-588, 
597-603. 

K. 

Kames  of  Cape  Ann,  Massachusetts,  549,  550. 
Kansas,  surveys  in,  3,  49,  56. 

Geologic  work  in,  104. 
Karl,  Anton,  work  of,  15,  60,  93,  94. 
Keith,  Arthur,  work  of,  76, 78. 
Kennedy, E.G., work  of, 66. 
Kentucky,  surveys  in,  4, 54. 

Topographic  work  in,  54. 
Knight,  F.  J. ,  work  of,  58. 
Knowlton,  F.  H.,  work  of,  138, 129, 130. 
Ktitzing,  cited  on  algae  in  hot  springs,  631. 
Lake  Agassiz,  investigation  of,  11, 12. 
La.ke  Superior  Division,  work  of,  10. 
Latimer,  George,  work  of,  141. 


Lea,  Isaac,  collection  of  minerals  and  fossils  given 
to  National  Museum  by,  136. 

Lead,  statistics,  135, 139. 

LeConte,  J.,  cited  on  precipitation  of  silica  at  Sul- 
phur Bank,  California,  656. 

Leighton,  George  B.,  aid  by,  74, 537. 

Lesquereux,  Leo,  work  of,  130. 

Leverett,  Frank,  work'  of,  13, 85. 

Library  and  documents,  work  of  Division  of,  31, 
145-151. 

Lime,  statistics,  187, 139. 

Lindgren,W.,work  of,  102. 

Lindsay,  Lauder,  cited  on  plants  in  hot  springs  of 
Iceland,  622. 

Lyman,  B.  S.,  cited  on  algous  growths  in  hot 
springs  of  Japan,  634. 

M. 

Mammoth  Hot  Springs,  Yellowstone  National 
Park,  character  of  waters  of,  638. 

Deposits  of,  629,650. 
Manganese,  statistics,  135,  139. 
Manigault,  G.  E. ,  aid  by,  310. 

Account  of  the  Charleston  earthquake  by, 

226-242. 

Maps  engraved,  5. 
Maps,  scale  of,  6, 7. 
Marcou,  J.  B.,  work  of,  105, 107, 108. 
Marls,  statistics,  137, 139. 
Marsh,  O.  C. ,  work  of,  30, 33. 

Report  of,  114,115. 

Marshes  of  Cape  Ann,  Massachusetts,  575, 576. 
Maryland,  surveys  in,  4, 52, 55. 
Massachusetts,  surveys  in,  4,49,50,51. 
Mayer,  analyses  of  siliceous  sinter  by,  670. 
McChesney,  J.  D.,  report  of,  153-199. 
McGee,  W.  J.,  work  of,  19, 30, 209. 

Report  of,  102-110. 
McKee,R.H.,58. 
McKinley,  Carl,  aid  by,  210. 

Account  of  Charleston  earthquake  by,  213-225. 
Melville,  W.  H. ,  work  of,  103. 
Mendenhall,  T.  C. ,  aid  by,  209. 
Meneghine,  cited  on  algse  in  hot  springs,  621. 
Merriam,  W.  N.,  work  of,  80, 81. 
Merrill,  G.  P., work  of,  113. 
Mesozoic  invertebrates,  work  of  Division  of,  120. 
Mica,  statistics,  137. 
Mineral  paints,  statistics,  137, 139. 
Mineral  waters,  statistics,  137, 139. 
Mining  statistics  and  technology,  report  of  division 

of,  134-140. 
Mining  statistics  and  technology,  work  of  Division 

of,  26-28. 

Mississippi,  geologic  work  in,  110. 
Missouri,  surveys  in,  4, 4fl,  56. 

Geologic  work  in,  103. 
Montana,  surveys  in,  4, 49, 59. 
Montana  Division  of  Geology,  work  of,  21, 111-114. 
Mosely,  H.  N.,  cited  on  algee  in  hot  springs  of 
the  Azores,  623. 

N. 

Natter,  E.  W.  F.,  work  of,50. 
Necrology,  31-48. 
Nell,  Louis,  work  of,  54. 
Nevada,  area  surveyed  in,  4. 


716 


INDEX. 


Newberry.J.  S  .work  of, 35. 

Report  of,  131,  1*!. 
New  Hampshire,  area  surveyed  iu,  4. 
New  Jersey,  survey  in, 4, 49,51,  ">-'. 
New  Jersey  marl  beds,  paleoutologic  work  in, 

138,  127. 

New  Mexico,  surveys  in,  4,  49,  58. 
New  York,  geologic  work  in,  105. 
New  Zealand,  plants  in  hot  springs  of,  622. 
New  Zealand  hot  spring  waters,  analyses,  673. 
Nickel,  statistics,  145, 139. 
Nordstedt,  Otto,  cited  on  algre  from  New  Zealand, 

622. 

North  Carolina,  surveys  in,  4, 54. 
Northeastern  section  of  geography,  work  of,  60. 
Northrop,  John  I., aid  by,  131. 
Novaculite,  statistics,  137, 140. 

O. 

Oregon,  surveys  in, -1,49,59. 

Owen,  D.  D.,  analysis  of  travertine  by,  846. 

P. 

Pacific  Coast  Division,  work  of,  13. 

Paleobotany,  work  of  Division  of,  128-131. 

Paleontologic  work,  progress  in,21~2»). 

Paleozoic  nshes  of  North  America,  monograph  of 
J.  H.  Newberry  on,  25. 

Paleozoic    invertebrates,    work   of    Division   of, 
11.V180. 

Parry,  C.  C.,  cited  on  algae  in  hot  springs  of  Yel- 
lowstone National  Park,  628. 

Partz,  Mrs. ,  cited  on  alga?  in  Benton  Spring.Owen's 
Valley,  Cal 

Peale,  A. C., cited  on  life  in  hot  springs  of  Yellow- 
stone National  Park,  62(1, 027. 
Work  of.  81. 
Report  of,  111-114. 

Peck, C.  H., cited  on  vegetation  of  hot  springs  of 
the  Yellowstone  National  Park,  628. 

Perkins,  E.  T,  work  of,  58. 

Peters,  W.J., 57. 

Petrography,  work  of  Division  of,  98-100. 

Ivin.lTOin,  statistics,  136,  139. 

Phinney ,  A.  J . ,  work  of,  103. 

Phosphate  rock,  statistics,  137, 139. 

Platinum,  statistics,  136, 13fl. 

Potomac    Division  of  Geology,  work  of,  19-21, 
102-110. 

Potter's  clay,  statistics,  137. 

Precious  stones,  statistics,  137,  140. 

Publications  of  U.    8.    Geological   Survey,  list, 
146-149. 

Publications,  table  showing  sales  of,  149, 150. 

Pumpelly,  R.,  work  of,  9, 10. 
Report  of,  75,76. 

Pyrites,  statistics,  137, 139. 


Quicksilver  deposits  investigated,  1-1. 
Quicksilver  deposits  of  the  Pacific  slope,  investi- 
gations of ,  100-101. 
Quicksilver,  statistics,  135, 139. 
Quinby,  G.  T. ,  aid  by ,  73, 74. 

R. 

Ragksky ,  analyses  of  hot  spring  waters  by,  639. 
Renshawe,  John  H.,work  of,  56. 


Rhode  Island,  topographic  work  in,  51. 
Area  surveyed  in,  4. 

Richmond,  C.W.,  work  of,  114. 

Ricksecker,  E.,  work  of,  58. 

Ridgway,  John  L.,work  of,  31. 

Kig(,-s,H.B.,work  of,  141. 

Rising,  W.  B.,  cited  on  precipitation  of  silica  at 
Sulphur  Bank,  Cal. ,  656. 

Robbins,  A.  H.,  work  of,  86. 

Rocky  Mountain  Division  of  Geology,  work  of, 
87-91. 

Roscoe,  H.  E.,  cited  on  deposition  of  silica  in  Ice- 
land geysers,  656. 

Rotorua,  siliceous  sinters  from,  673, 674, 675. 

Rubenhart,  cited  on  algse  in  hot  springs,  621. 

Russell, I.e., work  of, 76. 78. 

Rust,  W.  P.,  work  of,  117. 

Rutile,  statistics,  140. 

S. 

Salt,  statistics,  137, 139. 
Sayles,  Ira,  work  of,117,118. 
Scale  of  maps,  6, 7. 

Schaeffer,  Chas.  A. ,  acknowledgments  to,  109. 
Schlorlemmer,  cited  on  deposition  of  silica  in  Ice- 
land geysers,  656. 
Scudder,  H.  S.,  work  of,  28, 183. 
Seyler,  Hoppe,  on  algse  in  hot  springs  at  Lipari, 

621. 
Shaler,  N.  S.,work  of,  7,  8,  117. 

Report  of,  71-74. 

Paper  on  geology  of  Cape  Ann  by,  529-611. 
Shuster,  E.  H.,  work  of,  92. 
Siliceous  sinter,  origin  of,  650,651. 

Rate  of  deposition  of,  866, 667. 

Analyses  of,  670. 
Silver,  statistics,  135, 139. 
Slate  (ground),  statistics,  140. 
Sloan,  Earlc,  work  of,  209,  210. 
Smith,  J.  Lawrence,  analyses  of  hot  spring  waters 
by,  639. 

Analysis  of  travertine  by,  646. 
Smyth,  H.  L.,work  of,  76. 
South  Carolina,  area  surveyed  in,  4. 
Spenser,  W.  I.,  cited  on  plants  in  hot  springs  of 

New  Zealand,  622. 
Stearns,  R.  E.  C.,  work  of,  123. 124. 
Stevenson,  James,  biographical  sketch  of,  42-44. 
Stone,  George  H.,  work  of,  12, 87. 
Structural  materials,  statistics,  137. 
Sulphur,  statistics,  137, 139. 
Surveys,  American,  work  on  history  of,  107. 
Button,  Frank,  work  of,  51. 

Swamp  and  marsh  lands,  examination  of,  7,  8, 73, 
74. 

T. 

Table  showing  present  condition  of  topographic 
surveys,  3,  4. 

Taggart,  W.  R.,  cited  on  vegetation  of  hot  springs 
of  Yellowstone  National  Park,  626. 

Tarr,  R.  S. ,  work  of ,  72, 537. 

Thompson,  A.  H.,work  of,  57. 

Thompson,  Gilbert,  work  of,  52. 

Texas,  surveys  in,  4, 49, 57, 58. 

Paleontologic  work  in,  120.  , 

Work  on  bibliography  of  the  geology  of,  107. 


INDEX. 


717 


Tivoli,  vegetation  in  hot  springs  at,  645. 

Todd,  J.  E.,work  of,  12, 86. 

Topographic  drawing,  section  of,  6.3. 

Topographic  work,  progress  in,  3-7. 

Towson,  R.  M.,  work  of  ,55. 

Travertine  deposits  of  Mammoth  Hot  Springs, 

639,630. 
Travertine  and  siliceous  sinter,  paper  by  W.  II. 

Weed  on  formation  of,  613-676. 
Travertine,  table  of  analyses,  646. 
Turner,  H.  M., work  of,  IDS. 
Tweedy,  Frank,  59. 

U. 

Uinta  fold,  Colorado,  described ,  692-697. 
Uinta  sandstone,  geological  age  of,  687 
Upham,  Warren, work  of,  12, 84,85. 
Utah,  area  surveyed  in,  4. 

V. 

Van  Hise.C.  R.,work  of,  10,11. 

Report  of,  79. 

Vermeule,  C.  C.,  work  of,  52. 
Vermont,  area  surveyed  in.  4. 
Vertebrate  paleontology,  work  in,  i3. 

Work  of  division  of,  114,  115. 
Virginia,  geologic  work  in,  77. 

Surveys  in,  4,58-55. 
Volcanic  geology,  work  of  Division  of,  17-19,96-98. 

W. 

Walcott,  C.  D.,work  of,  23,  75. 

Report  of,  115-120. 
Wallace,  H.S.,  work  of,  57, 58.   • 
Ward,  L.  F.,  work  of,  25. 

Report  of,  128-131. 

Webster,  J.  W. ,  analyses  of  siliceous  sinter  by,  670. 
Weed,  W.  H. ,  work  of,  92, 96. 

Paper  by,  on  the  formation  of  travertine  and 
siliceous  sinter  by  the   vegetation  of  hot 
springs,  618-676. 
West  Virginia,  surveys  in,  4,  77. 
Western  section  of  geography,  57. 
Western  section  of  topography  ,57. 
White, C.  A.,  work  of, 24. 


White,  Charles  A.,  paper  by,  on   geology  and 

physiography  of  a  portion  of  northwestern 

Colorado  and  adjacent  parts  of  Utah  and 

Wyoming,  677-712. 
Report  of,  120-183. 
Whit.-.C.D.,work  of,  129,130. 
White,  I.  C. ,  work  of ,  13, 77. 
'.Vhitfield,  J.E.,and  F.  A.  Gooch,  analyses  of  hot 

spring  waters  by,  639,  655. 
Analyses  of  travertines  and  siliceous  sinter  by, 

646.670,675. 

Whittle,  C.  L. ,  work  of ,  75. 
Willcox,  Joseph,  work  of,  24, 125. 
Williams,  Albert,  jr.,  work  of,  87. 
Williams,  George  H.,work  of, 82,103. 
Williams,  H.  S.,  work  of,  117, 118. 
Williamson,  H.B.,  work  of,  98. 
Willis,  Bailey,  work  of,  76, 78. 
Wilson,  H.  M.,  work  of, 58. 
Wisconsin,  surveys  in,  4, 5, 49, 57. 
Wolff,J.E.,work  of, 75, 537. 
Wolle,  F.,  examination  of  plant  life  in  mud  of  hot 

springs,  669. 
Wood,  H.C..  cited  on  plant  growths  in  hot  springs 

of  California,  625. 
Woodward,  R.  S.,  report  of.  C9-71. 

Report  of,  to  chief  of  Division  of  Geography, 

68,69. 
Woodward,  R.  W.,  analyses  of  siliceous  sinter  by, 

670, 

Wooster,  L.  C. ,  work  of,  12, 86. 
Wyoming,  area  surveyed  in,  4. 

Y. 

Yampa  plateau,  described,  698, 699. 
Yeates,  C.  M.,  work  of,  54. 
Yellowstone  Lake,  work  at,  92, 93. 
Yellowstone  National  Park,  surveys  in,  4, 60. 

Work  in,  29, 96. 

Formation  of  hot  spring  deposits  in,  619. 

Plant  life  in  hot  springs  of.  625. 
Yellowstone  Park  Division,  work  of ,  15, 91. 


Zinc,  statistics,  135, 139. 
Zinc-whit*,  statistics,  139. 


5     31 


